Fixup bootloaders. (#16256)

keyboards/matrix/abelx/abelx.c

@@ -97,3 +97,8 @@ void shutdown_user(void)
     // set the magic number for resetting to the bootloader
     *(uint32_t *)(&(RTCD1.rtc->BKP0R)) = REBOOT_MAGIC;
 }
+
+void bootloader_jump(void) {
+    shutdown_user();
+    NVIC_SystemReset();
+}

keyboards/matrix/abelx/rules.mk

@@ -25,6 +25,9 @@ ARMV = 7
 
 USE_FPU = yes
 
+# Bootloader selection
+BOOTLOADER = custom
+
 # Build Options
 #   change yes to no to disable
 #

keyboards/matrix/m12og/rev1/rev1.c

@@ -20,6 +20,11 @@ void board_init(void) {
     writePinLow(A8);
 }
 
+void bootloader_jump(void) {
+    // This board doesn't use the standard DFU bootloader, and no information is available regarding how to enter bootloader mode. All we can do here is reset.
+    NVIC_SystemReset();
+}
+
 void keyboard_post_init_kb(void) {
     rgblight_enable_noeeprom();
     rgblight_sethsv_noeeprom(5, 255, 255);

keyboards/matrix/m12og/rev1/rules.mk

@@ -5,6 +5,9 @@ MCU_LDSCRIPT = m12og_v1
 
 BOARD = m12og_v1
 
+# Bootloader selection
+BOOTLOADER = custom
+
 # Build Options
 #   change yes to no to disable
 #

keyboards/matrix/m20add/m20add.c

@@ -59,3 +59,8 @@ void shutdown_user(void)
     // set the magic number for resetting to the bootloader
     *(uint32_t *)(&(RTCD1.rtc->BKP0R)) = REBOOT_MAGIC;
 }
+
+void bootloader_jump(void) {
+    shutdown_user();
+    NVIC_SystemReset();
+}

keyboards/matrix/m20add/rules.mk

@@ -10,6 +10,9 @@ MCU_LDSCRIPT = m20add_boot
 #  or <this_dir>/boards
 BOARD = ST_NUCLEO64_F411RE
 
+# Bootloader selection
+BOOTLOADER = custom
+
 # Build Options
 #   change yes to no to disable
 #

keyboards/matrix/noah/noah.c

@@ -4,6 +4,11 @@
 
 #include "noah.h"
 
+void bootloader_jump(void) {
+    // This board doesn't use the standard DFU bootloader, and no information is available regarding how to enter bootloader mode. All we can do here is reset.
+    NVIC_SystemReset();
+}
+
 #ifdef RGBLIGHT_ENABLE
 #include <string.h>
 #include "rgblight.h"

keyboards/matrix/noah/rules.mk

@@ -10,6 +10,9 @@ MCU_LDSCRIPT = noah_boot
 #  or <this_dir>/boards
 BOARD = ST_NUCLEO64_F411RE
 
+# Bootloader selection
+BOOTLOADER = custom
+
 # Build Options
 #   change yes to no to disable
 #