ASoC: Move bias level update to the core

All drivers have the same line at the end of the set_bias_level callback to
update the bias_level state. Move this update into
snd_soc_dapm_force_bias_level() and remove them from the drivers.

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

sound/soc/codecs/wm8750.c

@@ -651,7 +651,6 @@ static int wm8750_set_bias_level(struct snd_soc_codec *codec,
 		snd_soc_write(codec, WM8750_PWR1, 0x0001);
 		break;
 	}
-	codec->dapm.bias_level = level;
 	return 0;
 }