mmc: add support MMCIF for SuperH

MMCIF is the MMC Host Interface in SuperH.

Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>