Limit RGB brightness for crkbd when not defined (#13568)

keyboards/crkbd/post_config.h

@@ -29,3 +29,15 @@
 #ifndef BOOTMAGIC_LITE_COLUMN_RIGHT
 #    define BOOTMAGIC_LITE_COLUMN_RIGHT 1
 #endif
+
+#ifdef RGBLIGHT_ENABLE
+#    ifndef RGBLIGHT_LIMIT_VAL
+#        define RGBLIGHT_LIMIT_VAL 120
+#    endif
+#endif
+
+#ifdef RGB_MATRIX_ENABLE
+#    ifndef RGB_MATRIX_MAXIMUM_BRIGHTNESS
+#        define RGB_MATRIX_MAXIMUM_BRIGHTNESS 120
+#    endif
+#endif