Reboot into the ROM bootloader from 1200 baud

Per Scott, the purpose of this trick is to make the board programmable from Arduino even when CP is installed, so my convenience of escaping into UF2 is not going to work out.

Author: jepler

ports/espressif/supervisor/port.c

@@ -275,7 +275,7 @@ void reset_port(void) {
 }
 
 void reset_to_bootloader(void) {
-    common_hal_mcu_on_next_reset(RUNMODE_UF2);
+    common_hal_mcu_on_next_reset(RUNMODE_BOOTLOADER);
     esp_restart();
 }