Patch from Ben Dooks

timer_dyn_reprogram() fails with an OOPS if the
configuration for CONFIG_NO_IDLE_HZ is enabled, and
the system has no support for it.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>