ASoC: core: move definition of enum snd_soc_bias_level

To fix compilation error:

- error: field 'XXX' has incomplete type

Moves definition of enum snd_soc_bias_level from soc.h to soc-dapm.h.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20200625153543.85039-2-tzungbi@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h
index cc3dcb8..75467f2 100644
--- a/include/sound/soc-dapm.h
+++ b/include/sound/soc-dapm.h
@@ -376,6 +376,24 @@ struct snd_soc_dapm_widget_list;
 struct snd_soc_dapm_update;
 enum snd_soc_dapm_direction;
 
+/*
+ * Bias levels
+ *
+ * @ON:      Bias is fully on for audio playback and capture operations.
+ * @PREPARE: Prepare for audio operations. Called before DAPM switching for
+ *           stream start and stop operations.
+ * @STANDBY: Low power standby state when no playback/capture operations are
+ *           in progress. NOTE: The transition time between STANDBY and ON
+ *           should be as fast as possible and no longer than 10ms.
+ * @OFF:     Power Off. No restrictions on transition times.
+ */
+enum snd_soc_bias_level {
+	SND_SOC_BIAS_OFF = 0,
+	SND_SOC_BIAS_STANDBY = 1,
+	SND_SOC_BIAS_PREPARE = 2,
+	SND_SOC_BIAS_ON = 3,
+};
+
 int dapm_regulator_event(struct snd_soc_dapm_widget *w,
 			 struct snd_kcontrol *kcontrol, int event);
 int dapm_clock_event(struct snd_soc_dapm_widget *w,