ASoC: Set idle_bias_off flag in snd_soc_codec_driver

Since commit 33c5f969 "ASoC: Allow idle_bias_off to be specified in CODEC
drivers", now we can set idle_bias_off flag in struct snd_soc_codec_driver
for devices can unconditionally support idle_bias_off.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/wm8770.c b/sound/soc/codecs/wm8770.c
index 19374a9..bd60f84 100644
--- a/sound/soc/codecs/wm8770.c
+++ b/sound/soc/codecs/wm8770.c
@@ -580,8 +580,6 @@
 	wm8770 = snd_soc_codec_get_drvdata(codec);
 	wm8770->codec = codec;
 
-	codec->dapm.idle_bias_off = 1;
-
 	ret = snd_soc_codec_set_cache_io(codec, 7, 9, wm8770->control_type);
 	if (ret < 0) {
 		dev_err(codec->dev, "Failed to set cache I/O: %d\n", ret);
@@ -679,6 +677,7 @@
 	.suspend = wm8770_suspend,
 	.resume = wm8770_resume,
 	.set_bias_level = wm8770_set_bias_level,
+	.idle_bias_off = true,
 	.reg_cache_size = ARRAY_SIZE(wm8770_reg_defs),
 	.reg_word_size = sizeof (u16),
 	.reg_cache_default = wm8770_reg_defs