ASoC: fsl_esai: Mark expected switch fall-through

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

Addresses-Coverity-ID: 1222121 ("Missing break in switch")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_esai.c

@@ -249,6 +249,7 @@ static int fsl_esai_set_dai_sysclk(struct snd_soc_dai *dai, int clk_id,
 		break;
 	case ESAI_HCKT_EXTAL:
 		ecr |= ESAI_ECR_ETI;
+		/* fall through */
 	case ESAI_HCKR_EXTAL:
 		ecr |= ESAI_ECR_ERI;
 		break;