[ARM] 5470/1: U300 register definitions

This adds registers, interrupt numbers and IO mappings
for the U300 series platforms core support, including
basic block offsets and registers definitions for the
system controller.

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