mmc: sdhci-esdhc-imx: add MMC_CAP_1_8V_DDR for mx6

The i.MX6 supports 1.8v/3.3v eMMC DDR mode, so add this flag.
Signed-off-by: Dong Aisheng <b29396@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -1025,6 +1025,7 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	if (esdhc_is_usdhc(imx_data)) {
 		writel(0x08100810, host->ioaddr + ESDHC_WTMK_LVL);
 		host->quirks2 |= SDHCI_QUIRK2_PRESET_VALUE_BROKEN;
+		host->mmc->caps |= MMC_CAP_1_8V_DDR;
 	}
 
 	if (imx_data->socdata->flags & ESDHC_FLAG_MAN_TUNING)