Export add_timer_on for modules

Needed in followon patch.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

kernel/timer.c

@@ -756,6 +756,7 @@ void add_timer_on(struct timer_list *timer, int cpu)
 	wake_up_idle_cpu(cpu);
 	spin_unlock_irqrestore(&base->lock, flags);
 }
+EXPORT_SYMBOL_GPL(add_timer_on);
 
 /**
  * del_timer - deactive a timer.