timekeeping: access rtc outside of xtime lock

Lockdep complains about the access of rtc in timekeeping_suspend
inside the interrupt disabled region of the write locked xtime lock.
Move the access outside.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index acc417b..f682091 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -325,9 +325,10 @@
 {
 	unsigned long flags;
 
+	timekeeping_suspend_time = read_persistent_clock();
+
 	write_seqlock_irqsave(&xtime_lock, flags);
 	timekeeping_suspended = 1;
-	timekeeping_suspend_time = read_persistent_clock();
 	write_sequnlock_irqrestore(&xtime_lock, flags);
 
 	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);