ASoC: twl6040: 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.

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

sound/soc/codecs/twl6040.c

@@ -1095,25 +1095,6 @@ static struct snd_soc_dai_driver twl6040_dai[] = {
 },
 };
 
-#ifdef CONFIG_PM
-static int twl6040_suspend(struct snd_soc_codec *codec)
-{
-	twl6040_set_bias_level(codec, SND_SOC_BIAS_OFF);
-
-	return 0;
-}
-
-static int twl6040_resume(struct snd_soc_codec *codec)
-{
-	twl6040_set_bias_level(codec, SND_SOC_BIAS_STANDBY);
-
-	return 0;
-}
-#else
-#define twl6040_suspend NULL
-#define twl6040_resume NULL
-#endif
-
 static int twl6040_probe(struct snd_soc_codec *codec)
 {
 	struct twl6040_data *priv;
@@ -1160,19 +1141,17 @@ static int twl6040_remove(struct snd_soc_codec *codec)
 	struct twl6040_data *priv = snd_soc_codec_get_drvdata(codec);
 
 	free_irq(priv->plug_irq, codec);
-	twl6040_set_bias_level(codec, SND_SOC_BIAS_OFF);
 
 	return 0;
 }
 
 static struct snd_soc_codec_driver soc_codec_dev_twl6040 = {
 	.probe = twl6040_probe,
 	.remove = twl6040_remove,
-	.suspend = twl6040_suspend,
-	.resume = twl6040_resume,
 	.read = twl6040_read,
 	.write = twl6040_write,
 	.set_bias_level = twl6040_set_bias_level,
+	.suspend_bias_off = true,
 	.ignore_pmdown_time = true,
 
 	.controls = twl6040_snd_controls,