Fixup bootloaders. (#16256)

keyboards/ergodox_stm32/ergodox_stm32.c

@@ -16,6 +16,11 @@ void board_init(void) {
     AFIO->MAPR |= AFIO_MAPR_SWJ_CFG_JTAGDISABLE;
 }
 
+void bootloader_jump(void) {
+    // This board doesn't use the "standard" stm32duino bootloader, and is resident in memory at the base location. All we can do here is reset.
+    NVIC_SystemReset();
+}
+
 void matrix_init_kb(void)
 {
     // Init LED Ports

keyboards/ergodox_stm32/rules.mk

@@ -3,6 +3,9 @@ MCU = STM32F103
 MCU_LDSCRIPT = stm32f103_bootloader
 BOARD = ST_NUCLEO64_F103RB
 
+# Bootloader selection
+BOOTLOADER = custom
+
 BOOTMAGIC_ENABLE = no       # Enable Bootmagic Lite
 MOUSEKEY_ENABLE = no	# Mouse keys
 EXTRAKEY_ENABLE = yes	# Audio control and System control