ASoC: wm8955: Cleanup manual bias level transitions

Set the CODEC driver's suspend_bias_off flag rather than manually going to
SND_SOC_BIAS_OFF in suspend and SND_SOC_BIAS_STANDBY in resume. This makes
the code a bit shorter and cleaner. Also remove the regcache_mark_dirty()
from the suspend handler since this is already done by the ASoC core.

Since the ASoC core now takes care of setting the bias level to
SND_SOC_BIAS_OFF when removing the CODEC there is no need to do it manually
anymore either.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm8955.c

@@ -866,29 +866,6 @@ static struct snd_soc_dai_driver wm8955_dai = {
 	.ops = &wm8955_dai_ops,
 };
 
-#ifdef CONFIG_PM
-static int wm8955_suspend(struct snd_soc_codec *codec)
-{
-	struct wm8955_priv *wm8955 = snd_soc_codec_get_drvdata(codec);
-
-	wm8955_set_bias_level(codec, SND_SOC_BIAS_OFF);
-
-	regcache_mark_dirty(wm8955->regmap);
-
-	return 0;
-}
-
-static int wm8955_resume(struct snd_soc_codec *codec)
-{
-	wm8955_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
-
-	return 0;
-}
-#else
-#define wm8955_suspend NULL
-#define wm8955_resume NULL
-#endif
-
 static int wm8955_probe(struct snd_soc_codec *codec)
 {
 	struct wm8955_priv *wm8955 = snd_soc_codec_get_drvdata(codec);
@@ -964,18 +941,10 @@ static int wm8955_probe(struct snd_soc_codec *codec)
 	return ret;
 }
 
-static int wm8955_remove(struct snd_soc_codec *codec)
-{
-	wm8955_set_bias_level(codec, SND_SOC_BIAS_OFF);
-	return 0;
-}
-
 static struct snd_soc_codec_driver soc_codec_dev_wm8955 = {
 	.probe =	wm8955_probe,
-	.remove =	wm8955_remove,
-	.suspend =	wm8955_suspend,
-	.resume =	wm8955_resume,
 	.set_bias_level = wm8955_set_bias_level,
+	.suspend_bias_off = true,
 
 	.controls =	wm8955_snd_controls,
 	.num_controls = ARRAY_SIZE(wm8955_snd_controls),