sched: touch softlockup watchdog after idling

touch softlockup watchdog after idling.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -668,6 +668,7 @@ void sched_clock_idle_wakeup_event(u64 delta_ns)
 	struct rq *rq = cpu_rq(smp_processor_id());
 	u64 now = sched_clock();
 
+	touch_softlockup_watchdog();
 	rq->idle_clock += delta_ns;
 	/*
 	 * Override the previous timestamp and ignore all