Note that this relies on stuff currently in mfd's next tree, but this
is also a newer driver.  I'm not sure which tree it should go through,
as it's a problem that shows up in next.

From: Andres Salomon <dilinger@queued.net>

MFD changes in c738892f cause the mc13xxx_platform_data struct
to change.  This changes one more (new) user of it, fixing a build
error.
Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>