mmc: mmci: clarify DDR timing mode between SD-UHS and eMMC

Added MMC_DDR52 as eMMC's DDR mode distinguished from SD-UHS.

CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NSeungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NChris Ball <chris@printf.net>

drivers/mmc/host/mmci.c

@@ -299,7 +299,8 @@ static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
 		clk |= MCI_ST_8BIT_BUS;
 
-	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
+	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50 ||
+	    host->mmc->ios.timing == MMC_TIMING_MMC_DDR52)
 		clk |= MCI_ST_UX500_NEG_EDGE;
 
 	mmci_write_clkreg(host, clk);
@@ -784,7 +785,8 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
 			mmci_write_clkreg(host, clk);
 		}
 
-	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
+	if (host->mmc->ios.timing == MMC_TIMING_UHS_DDR50 ||
+	    host->mmc->ios.timing == MMC_TIMING_MMC_DDR52)
 		datactrl |= MCI_ST_DPSM_DDRMODE;
 
 	/*