timekeeping: rename timekeeping_is_continuous to timekeeping_valid_for_hres

Function timekeeping_is_continuous() no longer checks flag
CLOCK_IS_CONTINUOUS, and it checks CLOCK_SOURCE_VALID_FOR_HRES now.  So rename
the function accordingly.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 88267f0..fa9bb73 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -681,7 +681,7 @@
 	if (ts->nohz_mode != NOHZ_MODE_INACTIVE)
 		return 0;
 
-	if (!timekeeping_is_continuous() || !tick_is_oneshot_available())
+	if (!timekeeping_valid_for_hres() || !tick_is_oneshot_available())
 		return 0;
 
 	if (!allow_nohz)