ARM: 6832/1: mmci: support for ST-Ericsson db8500v2

ST-Ericsson modified ARM PrimeCell PL180 block has not got
an updated corresponding amba-id, althought the IP block has
changed in db8500v2. The change was done to the datactrl register.
Using the overrided subversion ID, account for this.

Signed-off-by: Philippe Langlais <philippe.langlais@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>