[Core] Add Reboot keycode to core (#15990)

platforms/chibios/bootloaders/stm32_dfu.c

@@ -61,6 +61,9 @@ __attribute__((weak)) void bootloader_jump(void) {
     NVIC_SystemReset();
 }
 
+__attribute__((weak)) void mcu_reset(void) {
+    NVIC_SystemReset();
+}
 // not needed at all, but if anybody attempts to invoke it....
 void enter_bootloader_mode_if_requested(void) {}
 
@@ -76,6 +79,10 @@ __attribute__((weak)) void bootloader_jump(void) {
     NVIC_SystemReset();
 }
 
+__attribute__((weak)) void mcu_reset(void) {
+    NVIC_SystemReset();
+}
+
 void enter_bootloader_mode_if_requested(void) {
     unsigned long *check = MAGIC_ADDR;
     if (*check == BOOTLOADER_MAGIC) {