mmc: pxamci compilation fix

since commit fcaf71fd51f9cfc504455d3e19ec242e4b2073ed
struct mmc_host does not have a dev field. Retrieve the device with
mmc_dev() instead.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
1 file changed