i.MX28 has four SSP/MMC units, only two of which are currently
usable.
Signed-off-by: NLothar Waßmann <LW@KARO-electronics.de>
Reviewed-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>