ASoC: rt5631: constify of_device_id array

of_device_id is always used as const.
(See driver.of_match_table and open firmware functions)

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/rt5631.c

@@ -1675,7 +1675,7 @@ static const struct i2c_device_id rt5631_i2c_id[] = {
 MODULE_DEVICE_TABLE(i2c, rt5631_i2c_id);
 
 #ifdef CONFIG_OF
-static struct of_device_id rt5631_i2c_dt_ids[] = {
+static const struct of_device_id rt5631_i2c_dt_ids[] = {
 	{ .compatible = "realtek,rt5631"},
 	{ .compatible = "realtek,alc5631"},
 	{ }