mmc: exynos_dw_mmc: enable the DDR mode

Set the ddr mode capability by default.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/drivers/mmc/exynos_dw_mmc.c b/drivers/mmc/exynos_dw_mmc.c
index 28941ad..d96dfe1 100644
--- a/drivers/mmc/exynos_dw_mmc.c
+++ b/drivers/mmc/exynos_dw_mmc.c
@@ -95,6 +95,7 @@
 			host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
 	}
 
+	host->caps = MMC_MODE_DDR_52MHz;
 	host->clksel = exynos_dwmci_clksel;
 	host->dev_index = index;
 	host->get_mmc_clk = exynos_dwmci_get_clk;