Option to prevent (extra) Watchdog init on STM32 (#19693)

Marlin/src/HAL/STM32/watchdog.cpp

   #include "watchdog.h"
   #include <IWatchdog.h>
 
-  void watchdog_init() { IWatchdog.begin(4000000); } // 4 sec timeout
+  void watchdog_init() {
+    #if DISABLED(DISABLE_WATCHDOG_INIT)
+      IWatchdog.begin(4000000); // 4 sec timeout
+    #endif
+  }
 
   void HAL_watchdog_refresh() {
     IWatchdog.reload();

Marlin/src/HAL/STM32F1/watchdog.cpp

  * @details The watchdog clock is 40Khz. We need a 4 seconds interval, so use a /256 preescaler and 625 reload value (counts down to 0)
  */
 void watchdog_init() {
-  //iwdg_init(IWDG_PRE_256, STM32F1_WD_RELOAD);
+  #if DISABLED(DISABLE_WATCHDOG_INIT)
+    iwdg_init(IWDG_PRE_256, STM32F1_WD_RELOAD);
+  #endif
 }
 
 #endif // USE_WATCHDOG

Marlin/src/pins/stm32f1/pins_MALYAN_M200.h

   #define BOARD_INFO_NAME "Malyan M200"
 #endif
 
+// Prevents hanging from an extra watchdog init
+#define DISABLE_WATCHDOG_INIT
+
 // Assume Flash EEPROM
 #if NO_EEPROM_SELECTED
   #define FLASH_EEPROM_EMULATION