MXS/MCI: don't touch variables in the host structure
MMC_BUS_WIDTH_* macros do not correspond with the real bus width.
After setting a bus width larger than 1 bit the next call to change the
frequency ends in the default handler and the host interface stays silently
at the previous frequency.
Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>