MXSFB: Fix driver registration

The driver should be registered with mxsfb_driver, not with mxsfb_devtype.
This caused obvious null pointer dereference and crash.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Huang Shijie <b32955@freescale.com>
Acked-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

drivers/video/mxsfb.c

@@ -902,7 +902,7 @@ static struct platform_driver mxsfb_driver = {
 	},
 };
 
-module_platform_driver(mxsfb_devtype);
+module_platform_driver(mxsfb_driver);
 
 MODULE_DESCRIPTION("Freescale mxs framebuffer driver");
 MODULE_AUTHOR("Sascha Hauer, Pengutronix");