ASoC: tlv320aic23: mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 146566
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/codecs/tlv320aic23.c

@@ -454,6 +454,7 @@ static int tlv320aic23_set_dai_fmt(struct snd_soc_dai *codec_dai,
 		break;
 	case SND_SOC_DAIFMT_DSP_A:
 		iface_reg |= TLV320AIC23_LRP_ON;
+		/* fall through */
 	case SND_SOC_DAIFMT_DSP_B:
 		iface_reg |= TLV320AIC23_FOR_DSP;
 		break;