ASoC: ak4642: prevent un-necessary changes to SG_SL1

If you record the sound during playback,
the playback sound becomes silent.
Modify so that the codec driver does not clear
SG_SL1::DACL bit which is controlled under widget
Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

sound/soc/codecs/ak4642.c

@@ -257,7 +257,7 @@ static int ak4642_dai_startup(struct snd_pcm_substream *substream,
 		 * This operation came from example code of
 		 * "ASAHI KASEI AK4642" (japanese) manual p94.
 		 */
-		snd_soc_write(codec, SG_SL1, PMMP | MGAIN0);
+		snd_soc_update_bits(codec, SG_SL1, PMMP | MGAIN0, PMMP | MGAIN0);
 		snd_soc_write(codec, TIMER, ZTM(0x3) | WTM(0x3));
 		snd_soc_write(codec, ALC_CTL1, ALC | LMTH0);
 		snd_soc_update_bits(codec, PW_MGMT1, PMADL, PMADL);