This fixes the build failures seen when building mpcore_wdt and it
also removes the nonexistent ARM_MPCORE_PLATFORM dependency, instead
make it dependent on HAVE_ARM_TWD.

Also this fixes spinlock usage appropriately.
Signed-off-by: Nsrinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>