ASoC: sgtl5000: fix VAG power up timing

When power up, a "pop" is heard on line-in and mic-in.
An analysis of the PCM shows it lasts ~400ms
and looks like a filter response.
VAG power up should be delayed by 400ms as VAG power down is.
Signed-off-by: Jean-Michel Hautbois <jean-michel.hautbois@veo-labs.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/sgtl5000.c

@@ -189,6 +189,7 @@ static int power_vag_event(struct snd_soc_dapm_widget *w,
 	case SND_SOC_DAPM_POST_PMU:
 		snd_soc_update_bits(codec, SGTL5000_CHIP_ANA_POWER,
 			SGTL5000_VAG_POWERUP, SGTL5000_VAG_POWERUP);
+		msleep(400);
 		break;
 
 	case SND_SOC_DAPM_PRE_PMD: