mmc: dw_mmc: fixed a wrong UHS_REG 16 bit clear

In the legacy code, driver clear not only UHS_REG 16 bit also 0-15bit.
If we use UHS-1 mode spec card like SDR50, SDR104. UHS_REG 0-15 should
be set by 1 according to slot id. In this case, legacy code can cause
problems.

In particular, UHS_REG consists of DDR_REG[31:16] and VOLT_REG[15:0].
Before adjusting this patch, bit[15:0] is always cleared.

Signed-off-by: Hyeonsu Kim <hyeonsu.kim@samsung.com>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/dw_mmc.c

@@ -795,9 +795,9 @@ static void dw_mci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	/* DDR mode set */
 	if (ios->timing == MMC_TIMING_UHS_DDR50)
-		regs |= (0x1 << slot->id) << 16;
+		regs |= ((0x1 << slot->id) << 16);
 	else
-		regs &= ~(0x1 << slot->id) << 16;
+		regs &= ~((0x1 << slot->id) << 16);
 
 	mci_writel(slot->host, UHS_REG, regs);