xen: resume timers on all vcpus

On resume, the vcpu timer modes will not be restored.  The timer
infrastructure doesn't do this for us, since it assumes the cpus
are offline.  We can just poke the other vcpus into the right mode
directly though.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index a457e03..9a05559 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -37,6 +37,7 @@
 unsigned long xen_get_wallclock(void);
 int xen_set_wallclock(unsigned long time);
 unsigned long long xen_sched_clock(void);
+void xen_timer_resume(void);
 
 irqreturn_t xen_debug_interrupt(int irq, void *dev_id);