Fix SKR Pro BLTouch conflicting timers (#16499)

Marlin/src/HAL/HAL_STM32/timers.h

   #define HAL_TIMER_RATE (F_CPU/2) // frequency of timer peripherals
 
   #ifndef STEP_TIMER
-    #define STEP_TIMER 5
+    #define STEP_TIMER 6
   #endif
 
   #ifndef TEMP_TIMER

buildroot/share/PlatformIO/variants/BIGTREE_SKR_PRO_1v1/PeripheralPins.c

   {PE_5,  TIM9,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 1, 0)}, // TIM9_CH1    FAN1
   {PE_6,  TIM9,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 2, 0)}, // TIM9_CH2    FAN2
   {PC_9,  TIM8,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM8, 4, 0)}, // TIM8_CH4    EXTENSION1-4
+  {PA_1,  TIM5,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 2, 0)}, // TIM5_CH2    BL-TOUCH-SERVO
+
+  // These pins have been defined for something else on the board but they MIGHT be
+  // used by the user as PWM pins if they aren't used for their primary purpose.
+  {PC_6,  TIM3,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1    ESP8266 connector. Available if 8266 isn't used
+  {PC_7,  TIM3,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2    ESP8266 connector. Available if 8266 isn't used
+  {PB_7,  TIM4,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 2, 0)}, // TIM4_CH2    I2C connector, SDA pin. Available if I2C isn't used.
+                                                                                       // TIM5_CH1    is used by the Servo Library
+  {PA_2,  TIM5,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 3, 0)}, // TIM5_CH3    BL-TOUCH port. Available if Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
 
   /**
    * Unused by specifications on SKR-Pro.
   //{PA_0,  TIM2,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 1, 0)}, // TIM2_CH1
   //{PA_0,  TIM5,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 1, 0)}, // TIM5_CH1
   //{PA_1,  TIM2,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 2, 0)}, // TIM2_CH2
-  //{PA_1,  TIM5,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 2, 0)}, // TIM5_CH2
   //{PA_2,  TIM2,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 3, 0)}, // TIM2_CH3
-  //{PA_2,  TIM5,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 3, 0)}, // TIM5_CH3
   //{PA_2,  TIM9,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM9, 1, 0)}, // TIM9_CH1
   //{PA_3,  TIM2,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM2, 4, 0)}, // TIM2_CH4
   //{PA_3,  TIM5,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM5, 4, 0)}, // TIM5_CH4
   //{PB_4,  TIM3,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
   //{PB_5,  TIM3,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
   //{PB_6,  TIM4,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 1, 0)}, // TIM4_CH1
-  //{PB_7,  TIM4,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 2, 0)}, // TIM4_CH2
   //{PB_8,  TIM4,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 3, 0)}, // TIM4_CH3
   //{PB_8,  TIM10,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM10, 1, 0)}, // TIM10_CH1
   //{PB_9,  TIM4,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM4, 4, 0)}, // TIM4_CH4
   //{PB_15, TIM1,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF1_TIM1, 3, 1)}, // TIM1_CH3N
   //{PB_15, TIM8,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM8, 3, 1)}, // TIM8_CH3N
   //{PB_15, TIM12,  STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF9_TIM12, 2, 0)}, // TIM12_CH2
-  //{PC_6,  TIM3,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 1, 0)}, // TIM3_CH1
   //{PC_6,  TIM8,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM8, 1, 0)}, // TIM8_CH1
   //{PC_7,  TIM3,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF2_TIM3, 2, 0)}, // TIM3_CH2
   //{PC_7,  TIM8,   STM_PIN_DATA_EXT(STM_MODE_AF_PP, GPIO_PULLUP, GPIO_AF3_TIM8, 2, 0)}, // TIM8_CH2

buildroot/share/PlatformIO/variants/BIGTREE_SKR_PRO_1v1/variant.h

 // Timer Definitions
 //Do not use timer used by PWM pins when possible. See PinMap_PWM in PeripheralPins.c
 #define TIMER_TONE              TIM2
+#define TIMER_SERVO             TIM5 // Only 1 Servo PIN on SKR-PRO, so use the same timer as defined in PeripheralPins
 #define TIMER_SERIAL            TIM7
 
-// Do not use basic timer: OC is required
-#define TIMER_SERVO             TIM6  //TODO: advanced-control timers don't work
-
 // UART Definitions
 //#define ENABLE_HWSERIAL1        done automatically by the #define SERIAL_UART_INSTANCE below
 #define ENABLE_HWSERIAL3