Allows device MMC boot partitions to be accessed. MMC partitions are
treated effectively as separate block devices on the same MMC card.
Signed-off-by: NAndrei Warkentin <andreiw@motorola.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NChris Ball <cjb@laptop.org>