ASoC: sgtl5000: Replace direct snd_soc_codec dapm field access

The dapm field of the snd_soc_codec struct is eventually going to be
removed, in preparation for this replace all manual access to
codec->dapm.bias_level with snd_soc_codec_get_bias_level().
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/sgtl5000.c

@@ -948,7 +948,7 @@ static int sgtl5000_set_bias_level(struct snd_soc_codec *codec,
 	case SND_SOC_BIAS_PREPARE:
 		break;
 	case SND_SOC_BIAS_STANDBY:
-		if (codec->dapm.bias_level == SND_SOC_BIAS_OFF) {
+		if (snd_soc_codec_get_bias_level(codec) == SND_SOC_BIAS_OFF) {
 			ret = regulator_bulk_enable(
 						ARRAY_SIZE(sgtl5000->supplies),
 						sgtl5000->supplies);