Watchdog cleanup (#15283)

Marlin/src/HAL/HAL_LPC1768/HAL.cpp

@@ -26,6 +26,10 @@
 #include "../shared/Delay.h"
 #include "../../../gcode/parser.h"
 
+#if ENABLED(USE_WATCHDOG)
+  #include "watchdog.h"
+#endif
+
 // U8glib required functions
 extern "C" void u8g_xMicroDelay(uint16_t val) {
   DELAY_US(val);
@@ -65,4 +69,17 @@ void flashFirmware(int16_t value) {
   NVIC_SystemReset();
 }
 
+void HAL_clear_reset_source(void) {
+  #if ENABLED(USE_WATCHDOG)
+    watchdog_clear_timeout_flag();
+  #endif
+}
+
+uint8_t HAL_get_reset_source(void) {
+  #if ENABLED(USE_WATCHDOG)
+    if (watchdog_timed_out()) return RST_WATCHDOG;
+  #endif
+  return RST_POWER_ON;
+}
+
 #endif // TARGET_LPC1768