clocksource: Get rid of cycle_last

cycle_last was added to the clocksource to support the TSC
validation. We moved that to the core code, so we can get rid of the
extra copy.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

arch/powerpc/kernel/time.c

@@ -741,7 +741,7 @@ static cycle_t timebase_read(struct clocksource *cs)
 }
 
 void update_vsyscall_old(struct timespec *wall_time, struct timespec *wtm,
-			struct clocksource *clock, u32 mult)
+			 struct clocksource *clock, u32 mult, cycle_t cycle_last)
 {
 	u64 new_tb_to_xs, new_stamp_xsec;
 	u32 frac_sec;
@@ -774,7 +774,7 @@ void update_vsyscall_old(struct timespec *wall_time, struct timespec *wtm,
 	 * We expect the caller to have done the first increment of
 	 * vdso_data->tb_update_count already.
 	 */
-	vdso_data->tb_orig_stamp = clock->cycle_last;
+	vdso_data->tb_orig_stamp = cycle_last;
 	vdso_data->stamp_xsec = new_stamp_xsec;
 	vdso_data->tb_to_xs = new_tb_to_xs;
 	vdso_data->wtom_clock_sec = wtm->tv_sec;