MMC: S3C24XX: Refuse incorrectly aligned transfers

The hardware does not support any multi-block transfers
with an block-size that is not 32bit aligned. Also the driver
itself does not support single block non-32bit transfers
either.

Ensure that the s3cmci_setup_data() returns the appropriate
error if we encounter this.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>