Support for Debug Codes - Dnnn (#19225)

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

Marlin/src/HAL/LINUX/HAL.h

@@ -101,6 +101,8 @@ uint16_t HAL_adc_get_result();
 inline void HAL_clear_reset_source(void) {}
 inline uint8_t HAL_get_reset_source(void) { return RST_POWER_ON; }
 
+inline void HAL_reboot() {}  // reboot the board or restart the bootloader
+
 /* ---------------- Delay in cycles */
 FORCE_INLINE static void DELAY_CYCLES(uint64_t x) {
   Clock::delayCycles(x);