The gpio-mxc controller complies with basic_mmio_gpio library.  The
patch convert the driver to use the library.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>