ARM: 5698/1: MMCI pass capabilities in platform data

This makes it possible to pass down the host controller
capabilities for the MMCI driver using the platform data. It
also provides the capabilties for the U300 implementation as an
example, and makes sure the 4bit wide mode is set if this is
requested by the ios() now that we can actually set that
capability for a platform.

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