mmc: tifm_sd: Mark expected switch fall-through

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

Notice that in this particular case, I replaced the
"deliberate fall-through" comment with a proper "fall through"
at the bottom of the case, which is what GCC is expecting to find.

Addresses-Coverity-ID: 1373887 ("Missing break in switch")
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/tifm_sd.c

@@ -336,7 +336,8 @@ static unsigned int tifm_sd_op_flags(struct mmc_command *cmd)
 		rc |= TIFM_MMCSD_RSP_R0;
 		break;
 	case MMC_RSP_R1B:
-		rc |= TIFM_MMCSD_RSP_BUSY; // deliberate fall-through
+		rc |= TIFM_MMCSD_RSP_BUSY;
+		/* fall-through */
 	case MMC_RSP_R1:
 		rc |= TIFM_MMCSD_RSP_R1;
 		break;