ASoC: wm8997: Use async writes

When writing the patch write to the device asynchronously, allowing better
performance when used with a bus like SPI which supports this by
minimising the need to context switch back to the driver to get the
next bit of data.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8997.c

@@ -103,8 +103,8 @@ static int wm8997_sysclk_ev(struct snd_soc_dapm_widget *w,
 	case SND_SOC_DAPM_POST_PMU:
 		if (patch)
 			for (i = 0; i < patch_size; i++)
-				regmap_write(regmap, patch[i].reg,
-					     patch[i].def);
+				regmap_write_async(regmap, patch[i].reg,
+						   patch[i].def);
 		break;
 	default:
 		break;