ARM: 6437/2: mmci: add some register defines for ST Micro variants

This adds a few registers to the MMCI/PL180 derivates that
is used for some odd control stuff like SDIO.

Signed-off-by: Marcin Mielczarczyk <marcin.mielczarczyk@tieto.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>