[NOT-FOR-UPSTREAM] drivers: video: backlight: Disable backlight notification events

We don't want to generate udev events for brightness changes on Steam
Deck, as some games like Celeste will re-enumerate controller devices in
response to this event.

Patch from Sam Lantinga.

(cherry picked from commit 85da5a5)
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>

Author: Plagman

drivers/video/backlight/backlight.c

@@ -160,6 +160,7 @@ static inline void backlight_unregister_fb(struct backlight_device *bd)
 static void backlight_generate_event(struct backlight_device *bd,
 				     enum backlight_update_reason reason)
 {
+#if 0 // We don't want to generate udev events for brightness changes on Steam Deck, as some games like Celeste will re-enumerate controller devices in response to this event.
 	char *envp[2];
 
 	switch (reason) {
@@ -175,6 +176,7 @@ static void backlight_generate_event(struct backlight_device *bd,
 	}
 	envp[1] = NULL;
 	kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp);
+#endif // 0
 	sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
 }