This adds the mmc host driver for Freescale MXS-based SoC i.MX23/28.
The driver calls into mxs-dma via generic dmaengine api for both pio
and data transfer.

Thanks Chris Ball for the indentation patch.
Signed-off-by: NShawn Guo <shawn.guo@freescale.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Tested-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NChris Ball <cjb@laptop.org>