ASoC: atmel_wm8904: add snd_soc_pm_ops

Sometimes the audio play can not be resumed after it is
suspended. Add snd_soc_pm_ops to execute power management
operations, then this issue is fixed.
Signed-off-by: Songjun Wu <songjun.wu@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/atmel/atmel_wm8904.c

@@ -183,6 +183,7 @@ static struct platform_driver atmel_asoc_wm8904_driver = {
 	.driver = {
 		.name = "atmel-wm8904-audio",
 		.of_match_table = of_match_ptr(atmel_asoc_wm8904_dt_ids),
+		.pm		= &snd_soc_pm_ops,
 	},
 	.probe = atmel_asoc_wm8904_probe,
 	.remove = atmel_asoc_wm8904_remove,