Input: gpio_keys - make of_device_id array const

Make of_device_id array const, because all OF functions handle it as const.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/gpio_keys.c

@@ -646,7 +646,7 @@ gpio_keys_get_devtree_pdata(struct device *dev)
 	return pdata;
 }
 
-static struct of_device_id gpio_keys_of_match[] = {
+static const struct of_device_id gpio_keys_of_match[] = {
 	{ .compatible = "gpio-keys", },
 	{ },
 };