mmc: sdhci-s3c: fix the wrong register value, when clock is disabled

When use the QUIRK_NONSTANDARD_CLOCK, then never set to 0 at clock control
register.  This patch fixes this problem.
Signed-off-by: NJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NChris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-s3c.c

@@ -296,9 +296,12 @@ static void sdhci_cmu_set_clock(struct sdhci_host *host, unsigned int clock)
 	unsigned long timeout;
 	u16 clk = 0;
 
-	/* don't bother if the clock is going off */
-	if (clock == 0)
+	/* If the clock is going off, set to 0 at clock control register */
+	if (clock == 0) {
+		sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
+		host->clock = clock;
 		return;
+	}
 
 	sdhci_s3c_set_clock(host, clock);