Fix a few recent (STM32F1 DOGM, SPI) warnings (#14669)

Marlin/src/HAL/HAL_STM32F1/HAL.cpp

 void HAL_adc_init(void) {
   // configure the ADC
   adc.calibrate();
-  adc.setSampleRate(ADC_SMPR_41_5); // ?
+  #if F_CPU > 72000000
+    adc.setSampleRate(ADC_SMPR_71_5); // 71.5 ADC cycles
+  #else
+    adc.setSampleRate(ADC_SMPR_41_5); // 41.5 ADC cycles
+  #endif
   adc.setPins(adc_pins, ADC_PIN_COUNT);
   adc.setDMA(HAL_adc_results, (uint16_t)ADC_PIN_COUNT, (uint32_t)(DMA_MINC_MODE | DMA_CIRC_MODE), nullptr);
   adc.setScanMode();

Marlin/src/HAL/HAL_STM32F1/HAL_spi_STM32F1.cpp

  * @details
  */
 uint8_t spiRec(void) {
-  uint8_t returnByte = SPI.transfer(0xFF);
+  uint8_t returnByte = SPI.transfer(ff);
   return returnByte;
 }
 

Marlin/src/HAL/HAL_STM32F1/STM32F1_flag_script.py

 #dynamic build flags for generic compile options
 if __name__ == "__main__":
   args = " ".join([ "-std=gnu11",
-                    "-std=gnu++11",
                     "-Os",
                     "-mcpu=cortex-m3",
                     "-mthumb",

Marlin/src/lcd/dogm/HAL_LCD_com_defines.h

 
 #ifndef U8G_HAL_LINKS
 
-
   #ifdef __SAM3X8E__
     uint8_t u8g_com_HAL_DUE_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_SW_SPI_FN  u8g_com_HAL_DUE_sw_spi_fn
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_HAL_DUE_shared_hw_spi_fn
     uint8_t u8g_com_HAL_DUE_ST7920_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_HAL_DUE_ST7920_sw_spi_fn
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
   #elif defined(__STM32F1__)
     uint8_t u8g_com_HAL_STM32F1_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_SW_SPI_FN u8g_com_HAL_STM32F1_sw_spi_fn
-    uint8_t u8g_com_arduino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-    //#define U8G_COM_HAL_HW_SPI_FN u8g_com_arduino_hw_spi_fn
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_stm32duino_hw_spi_fn
-    uint8_t u8g_com_arduino_st7920_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-    //#define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_std_sw_spi_fn
     #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_stm32duino_hw_spi_fn
   #elif defined(ARDUINO_ARCH_STM32)
-    uint8_t u8g_com_arduino_std_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_SW_SPI_FN u8g_com_arduino_std_sw_spi_fn
-    uint8_t u8g_com_stm32duino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_stm32duino_hw_spi_fn
-    uint8_t u8g_com_arduino_st7920_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
-  #else
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_stm32duino_hw_spi_fn
+  #elif defined(__AVR__)
     uint8_t u8g_com_HAL_AVR_sw_sp_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-    #define U8G_COM_HAL_SW_SPI_FN  u8g_com_HAL_AVR_sw_sp_fn // AVR ?
-    uint8_t u8g_com_arduino_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
+    #define U8G_COM_HAL_SW_SPI_FN  u8g_com_HAL_AVR_sw_sp_fn
     #define U8G_COM_HAL_HW_SPI_FN u8g_com_arduino_hw_spi_fn
-    uint8_t u8g_com_arduino_st7920_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
+  #else
+    #define U8G_COM_HAL_SW_SPI_FN u8g_com_arduino_std_sw_spi_fn
+    #define U8G_COM_HAL_HW_SPI_FN u8g_com_arduino_hw_spi_fn
+    #define U8G_COM_ST7920_HAL_SW_SPI u8g_com_arduino_st7920_spi_fn
+    #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
   #endif
 
-  uint8_t u8g_com_arduino_st7920_hw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
-  #define U8G_COM_ST7920_HAL_HW_SPI u8g_com_arduino_st7920_hw_spi_fn
-
   uint8_t u8g_com_HAL_LPC1768_ssd_hw_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
   #define U8G_COM_SSD_I2C_HAL u8g_com_arduino_ssd_i2c_fn
 
-  #if defined(ARDUINO_ARCH_STM32F1) && PIN_EXISTS(FSMC_CS)
+  #if PIN_EXISTS(FSMC_CS)
     uint8_t u8g_com_stm32duino_fsmc_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
     #define U8G_COM_HAL_FSMC_FN u8g_com_stm32duino_fsmc_fn
   #else
     #define U8G_COM_HAL_FSMC_FN u8g_com_null_fn
   #endif
+
 #elif TARGET_LPC1768
   uint8_t u8g_com_HAL_LPC1768_sw_spi_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
   #define U8G_COM_HAL_SW_SPI_FN u8g_com_HAL_LPC1768_sw_spi_fn

Marlin/src/lcd/dogm/u8g_dev_tft_320x240_upscale_from_128x64.cpp

   #else
     uint16_t buffer[256]; // 16-bit RGB 565 pixel line buffer
   #endif
-  uint16_t i;
   switch (msg) {
     case U8G_DEV_MSG_INIT:
       dev->com_fn(u8g, U8G_COM_MSG_INIT, U8G_SPI_CLK_CYCLE_NONE, &lcd_id);

config/examples/Alfawise/U20/Configuration.h

   // Middle point of circle
   #define NOZZLE_CLEAN_CIRCLE_MIDDLE NOZZLE_CLEAN_START_POINT
 
-  // Moves the nozzle to the initial position
+  // Move the nozzle to the initial position after cleaning
   #define NOZZLE_CLEAN_GOBACK
+
+  // Enable for a purge/clean station that's always at the gantry height (thus no Z move)
+  //#define NOZZLE_CLEAN_NO_Z
 #endif
 
 /**
 #define MKS_ROBIN_TFT
 
 //=============================================================================
-//============================= SPI Touch Screens =============================
+//============================  Other Controllers  ============================
 //=============================================================================
 
 #define TOUCH_BUTTONS
   #endif
 #endif
 
-//=============================================================================
-//============================  Other Controllers  ============================
-//=============================================================================
-
-//
-// CONTROLLER TYPE: Keypad / Add-on
-//
-
 //
 // RepRapWorld REPRAPWORLD_KEYPAD v1.1
 // http://reprapworld.com/?products_details&products_id=202&cPath=1591_1626