ASoC: max98373: Added 30ms turn on/off time delay

Amp requires 10 ~ 30ms for the power ON and OFF.
Added 30ms delay for stability.
Signed-off-by: Ryan Lee <ryans.lee@maximintegrated.com>
Link: https://lore.kernel.org/r/20210325033555.29377-2-ryans.lee@maximintegrated.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/max98373.c

@@ -28,11 +28,13 @@ static int max98373_dac_event(struct snd_soc_dapm_widget *w,
 		regmap_update_bits(max98373->regmap,
 			MAX98373_R20FF_GLOBAL_SHDN,
 			MAX98373_GLOBAL_EN_MASK, 1);
+		usleep_range(30000, 31000);
 		break;
 	case SND_SOC_DAPM_POST_PMD:
 		regmap_update_bits(max98373->regmap,
 			MAX98373_R20FF_GLOBAL_SHDN,
 			MAX98373_GLOBAL_EN_MASK, 0);
+		usleep_range(30000, 31000);
 		max98373->tdm_mode = false;
 		break;
 	default: