ARM: 6201/1: RealView: Do not use outer_sync() on ARM11MPCore boards with L220

RealView boards with certain revisions of the L220 cache controller (ARM11*
processors only) may have issues (hardware deadlock) with the recent changes to
the mb() barrier implementation (DSB followed by an L2 cache sync). The patch
redefines the RealView ARM11MPCore mandatory barriers without the outer_sync()
call.

Cc: <stable@kernel.org>
Tested-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>