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/atmel-pwm-bl.c b/drivers/video/backlight/atmel-pwm-bl.c
index 2cf7ba5..f625ffc 100644
--- a/drivers/video/backlight/atmel-pwm-bl.c
+++ b/drivers/video/backlight/atmel-pwm-bl.c
@@ -113,7 +113,7 @@
 	return pwm_channel_enable(&pwmbl->pwmc);
 }
 
-static struct backlight_ops atmel_pwm_bl_ops = {
+static const struct backlight_ops atmel_pwm_bl_ops = {
 	.get_brightness = atmel_pwm_bl_get_intensity,
 	.update_status  = atmel_pwm_bl_set_intensity,
 };