[ARM] 3527/1: MPCore Boot Lockup Fix

Patch from Harry Fearnhamm

This patch fixes the occasional lockup seen in early boot stage
on RealView MPCore system.

Signed-off-by: Harry Fearnhamm <Harry.Fearnhamm@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>