RetroFW: Fix brightness button using belt item 3

CMakeLists.txt

@@ -325,6 +325,7 @@ foreach(
   KBCTRL_BUTTON_START
   KBCTRL_BUTTON_BACK
   KBCTRL_MODIFIER_KEY
+  KBCTRL_IGNORE_1
   JOY_AXIS_LEFTX
   JOY_AXIS_LEFTY
   JOY_AXIS_RIGHTX

Packaging/OpenDingux/build.sh

@@ -130,6 +130,7 @@ build() {
 			-DKBCTRL_BUTTON_START=SDLK_RETURN
 			-DKBCTRL_BUTTON_LEFTSTICK=SDLK_END # Suspend
 			-DKBCTRL_MODIFIER_KEY=SDLK_ESCAPE # Select
+			-DKBCTRL_IGNORE_1=SDLK_3 # Backlight
 		)
 	fi
 	cmake .. ${defs[@]} \

SourceX/controls/devices/kbcontroller.cpp

@@ -28,6 +28,10 @@ ControllerButton KbCtrlToControllerButton(const SDL_Event &event)
 	case SDL_KEYDOWN:
 	case SDL_KEYUP:
 		switch (event.key.keysym.sym) {
+#ifdef KBCTRL_IGNORE_1
+		case KBCTRL_IGNORE_1:
+			return ControllerButton::IGNORE;
+#endif
 #ifdef KBCTRL_MODIFIER_KEY
 		case KBCTRL_MODIFIER_KEY:
 			return ControllerButton::IGNORE;