ASoC: wm8974: 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.

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>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm8974.c

@@ -568,18 +568,6 @@ static struct snd_soc_dai_driver wm8974_dai = {
 	.symmetric_rates = 1,
 };
 
-static int wm8974_suspend(struct snd_soc_codec *codec)
-{
-	wm8974_set_bias_level(codec, SND_SOC_BIAS_OFF);
-	return 0;
-}
-
-static int wm8974_resume(struct snd_soc_codec *codec)
-{
-	wm8974_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
-	return 0;
-}
-
 static const struct regmap_config wm8974_regmap = {
 	.reg_bits = 7,
 	.val_bits = 9,
@@ -599,24 +587,13 @@ static int wm8974_probe(struct snd_soc_codec *codec)
 		return ret;
 	}
 
-	wm8974_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
-
-	return ret;
-}
-
-/* power down chip */
-static int wm8974_remove(struct snd_soc_codec *codec)
-{
-	wm8974_set_bias_level(codec, SND_SOC_BIAS_OFF);
 	return 0;
 }
 
 static struct snd_soc_codec_driver soc_codec_dev_wm8974 = {
 	.probe = 	wm8974_probe,
-	.remove = 	wm8974_remove,
-	.suspend = 	wm8974_suspend,
-	.resume =	wm8974_resume,
 	.set_bias_level = wm8974_set_bias_level,
+	.suspend_bias_off = true,
 
 	.controls = wm8974_snd_controls,
 	.num_controls = ARRAY_SIZE(wm8974_snd_controls),