mmc: sh_mmcif: cosmetic clean up

Replace pr_* with respective dev_*, sort headers alphabetically, remove an
unused struct member, superfluous variable initialisations and type-casts.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>