ASoC: tlv320aic32x4: Use snd_soc_update_bits() in aic32x4_mute()

Simplify mute function by using snd_soc_update_bits() over
read/modify/write style code.
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/tlv320aic32x4.c

@@ -773,13 +773,10 @@ static int aic32x4_hw_params(struct snd_pcm_substream *substream,
 static int aic32x4_mute(struct snd_soc_dai *dai, int mute)
 {
 	struct snd_soc_codec *codec = dai->codec;
-	u8 dac_reg;
 
-	dac_reg = snd_soc_read(codec, AIC32X4_DACMUTE) & ~AIC32X4_MUTEON;
-	if (mute)
-		snd_soc_write(codec, AIC32X4_DACMUTE, dac_reg | AIC32X4_MUTEON);
-	else
-		snd_soc_write(codec, AIC32X4_DACMUTE, dac_reg);
+	snd_soc_update_bits(codec, AIC32X4_DACMUTE,
+			    AIC32X4_MUTEON, mute ? AIC32X4_MUTEON : 0);
+
 	return 0;
 }