mmc: sdhci-esdhc-imx: change pinctrl state according to uhs mode

Without proper pinctrl state, the card may not be able to work
on high speed stablely. e.g. SDR104.

This patch add pinctrl state switch code according to different
uhs mode include 100mhz sate, 200mhz sate and normal state
(50Mhz and below).

Signed-off-by: Dong Aisheng <b29396@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>