pinctrl: add VF610 pinctrl driver

Adds Freescale Vybrid VF610 pin controller
driver to IMX common pinctrl driver framework.

Signed-off-by: Jingchang Lu <b35083@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>