timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset

update_vsyscall() did not provide the wall_to_monotoinc offset,
so arch specific implementations tend to reference wall_to_monotonic
directly. This limits future cleanups in the timekeeping core, so
this patch fixes the update_vsyscall interface to provide
wall_to_monotonic, allowing wall_to_monotonic to be made static
as planned in Documentation/feature-removal-schedule.txt

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tony Luck <tony.luck@intel.com>
LKML-Reference: <1279068988-21864-7-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 5ea3c60..21677d9 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -313,11 +313,13 @@
 
 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
 extern void
-update_vsyscall(struct timespec *ts, struct clocksource *c, u32 mult);
+update_vsyscall(struct timespec *ts, struct timespec *wtm,
+			struct clocksource *c, u32 mult);
 extern void update_vsyscall_tz(void);
 #else
 static inline void
-update_vsyscall(struct timespec *ts, struct clocksource *c, u32 mult)
+update_vsyscall(struct timespec *ts, struct timespec *wtm,
+			struct clocksource *c, u32 mult)
 {
 }