[ARM] 5480/1: U300-v5 integrate into the ARM architecture

This hooks the U300 support into Kbuild and makes a small hook
in mmu.c for supporting an odd memory alignment with shared memory
on these systems.

This is rebased to RMK:s GIT HEAD. This patch tries to add the
Kconfig option in alphabetic order by option text and the Makefile
entry after config symbol.

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