xen: Fix compile error introduced by "switch to new irq_chip functions"

drivers/xen/events.c: In function 'ack_pirq':
drivers/xen/events.c:568: error: implicit declaration of function 'irq_move_irq'

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/events.c

@@ -553,7 +553,7 @@ static void ack_pirq(struct irq_data *data)
 {
 	int evtchn = evtchn_from_irq(data->irq);
 
-	irq_move_irq(data);
+	move_native_irq(data->irq);
 
 	if (VALID_EVTCHN(evtchn)) {
 		mask_evtchn(evtchn);