[CPUFREQ] use deferrable delayed work init in conservative governor

Venki Pallipadi made a similar change to the ondemand governor a while
back (in commit 28287033). It seems to
work just as well in the conservative governor, leading to fewer wakeups
as reported by powertop.
Signed-off-by: NBen Slusky <sluskyb@paranoiacs.org>
Signed-off-by: NDave Jones <davej@redhat.com>

drivers/cpufreq/cpufreq_conservative.c

@@ -460,6 +460,7 @@ static void do_dbs_timer(struct work_struct *work)
 
 static inline void dbs_timer_init(void)
 {
+	init_timer_deferrable(&dbs_work.timer);
 	schedule_delayed_work(&dbs_work,
 			usecs_to_jiffies(dbs_tuners_ins.sampling_rate));
 	return;