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/tosa_bl.c b/drivers/video/backlight/tosa_bl.c
index 43edbad..e14ce4d 100644
--- a/drivers/video/backlight/tosa_bl.c
+++ b/drivers/video/backlight/tosa_bl.c
@@ -72,7 +72,7 @@
 	return props->brightness;
 }
 
-static struct backlight_ops bl_ops = {
+static const struct backlight_ops bl_ops = {
 	.get_brightness		= tosa_bl_get_brightness,
 	.update_status		= tosa_bl_update_status,
 };