ASoC: wm8988: 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 it is already called 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.

The manual transition to SND_SOC_BIAS_STANDBY at the end of CODEC probe()
can also be removed as the core will automatically do this after the CODEC
has been probed.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm8988.c

@@ -793,21 +793,6 @@ static struct snd_soc_dai_driver wm8988_dai = {
 	.symmetric_rates = 1,
 };
 
-static int wm8988_suspend(struct snd_soc_codec *codec)
-{
-	struct wm8988_priv *wm8988 = snd_soc_codec_get_drvdata(codec);
-
-	wm8988_set_bias_level(codec, SND_SOC_BIAS_OFF);
-	regcache_mark_dirty(wm8988->regmap);
-	return 0;
-}
-
-static int wm8988_resume(struct snd_soc_codec *codec)
-{
-	wm8988_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
-	return 0;
-}
-
 static int wm8988_probe(struct snd_soc_codec *codec)
 {
 	int ret = 0;
@@ -825,23 +810,13 @@ static int wm8988_probe(struct snd_soc_codec *codec)
 	snd_soc_update_bits(codec, WM8988_ROUT2V, 0x0100, 0x0100);
 	snd_soc_update_bits(codec, WM8988_RINVOL, 0x0100, 0x0100);
 
-	wm8988_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
-
-	return 0;
-}
-
-static int wm8988_remove(struct snd_soc_codec *codec)
-{
-	wm8988_set_bias_level(codec, SND_SOC_BIAS_OFF);
 	return 0;
 }
 
 static struct snd_soc_codec_driver soc_codec_dev_wm8988 = {
 	.probe =	wm8988_probe,
-	.remove =	wm8988_remove,
-	.suspend =	wm8988_suspend,
-	.resume =	wm8988_resume,
 	.set_bias_level = wm8988_set_bias_level,
+	.suspend_bias_off = true,
 
 	.controls = wm8988_snd_controls,
 	.num_controls = ARRAY_SIZE(wm8988_snd_controls),