[MMC] Fix incorrect register access

There was a writel() being used on a 16-bit register.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

drivers/mmc/sdhci.c

@@ -565,7 +565,7 @@ static void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
 	if (cmd->data)
 		flags |= SDHCI_CMD_DATA;
 
-	writel(SDHCI_MAKE_CMD(cmd->opcode, flags),
+	writew(SDHCI_MAKE_CMD(cmd->opcode, flags),
 		host->ioaddr + SDHCI_COMMAND);
 }