mmc: sdhci-esdhc-imx: increase the pad I/O drive strength for DDR50 card

Currently for DDR50 card, it need tuning in default. We meet tuning fail
issue for DDR50 card and some data CRC error when DDR50 sd card works.

This is because the default pad I/O drive strength can't make sure DDR50
card work stable. So increase the pad I/O drive strength for DDR50 card,
and use pins_100mhz.

This fixes DDR50 card support for IMX since DDR50 tuning was enabled from
commit 9faac7b9 ("mmc: sdhci: enable tuning for DDR50")
Tested-and-reported-by: NTim Harvey <tharvey@gateworks.com>
Signed-off-by: NHaibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org # v4.4+
Acked-by: NDong Aisheng <aisheng.dong@nxp.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

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

@@ -830,6 +830,7 @@ static int esdhc_change_pinstate(struct sdhci_host *host,
 
 	switch (uhs) {
 	case MMC_TIMING_UHS_SDR50:
+	case MMC_TIMING_UHS_DDR50:
 		pinctrl = imx_data->pins_100mhz;
 		break;
 	case MMC_TIMING_UHS_SDR104: