Patch from Lennert Buytenhek

A couple of platforms aren't using the right comparison type in their
timer interrupt handlers (as we're comparing two wrapping timestamps,
we need a bmi/bpl-type comparison, not an unsigned comparison) -- this
patch fixes them up.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>