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/wm831x_bl.c b/drivers/video/backlight/wm831x_bl.c
index 467bdb7..e32add3 100644
--- a/drivers/video/backlight/wm831x_bl.c
+++ b/drivers/video/backlight/wm831x_bl.c
@@ -112,7 +112,7 @@
 	return data->current_brightness;
 }
 
-static struct backlight_ops wm831x_backlight_ops = {
+static const struct backlight_ops wm831x_backlight_ops = {
 	.options = BL_CORE_SUSPENDRESUME,
 	.update_status	= wm831x_backlight_update_status,
 	.get_brightness	= wm831x_backlight_get_brightness,