Soft Reset via Serial or post-kill button click (#21652)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

Marlin/src/HAL/ESP32/HAL.cpp

@@ -141,6 +141,8 @@ void HAL_clear_reset_source() { }
 
 uint8_t HAL_get_reset_source() { return rtc_get_reset_reason(1); }
 
+void HAL_reboot() { ESP.restart(); }
+
 void _delay_ms(int delay_ms) { delay(delay_ms); }
 
 // return free memory between end of heap (or end bss) and whatever is current

Marlin/src/HAL/ESP32/HAL.h

@@ -101,7 +101,7 @@ void HAL_clear_reset_source();
 // reset reason
 uint8_t HAL_get_reset_source();
 
-inline void HAL_reboot() {}  // reboot the board or restart the bootloader
+void HAL_reboot();
 
 void _delay_ms(int delay);