hwmon: (iio_hwmon) 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: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/iio_hwmon.c

@@ -163,7 +163,7 @@ static int iio_hwmon_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct of_device_id iio_hwmon_of_match[] = {
+static const struct of_device_id iio_hwmon_of_match[] = {
 	{ .compatible = "iio-hwmon", },
 	{ }
 };