pinctrl: imx27: imx27 pincontrol driver

imx27 pincontrol driver using the imx1 core driver. The DT bindings are
similar to other imx pincontrol drivers.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>