backlight: Constify struct backlight_ops

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 6615ac7..18829cf 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -269,7 +269,7 @@
  * ERR_PTR() or a pointer to the newly allocated device.
  */
 struct backlight_device *backlight_device_register(const char *name,
-		struct device *parent, void *devdata, struct backlight_ops *ops)
+		struct device *parent, void *devdata, const struct backlight_ops *ops)
 {
 	struct backlight_device *new_bd;
 	int rc;