xen: support pirq != irq

PHYSDEVOP_map_pirq might return a pirq different from what we asked if
we are running as an HVM guest, so we need to be able to support pirqs
that are different from linux irqs.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/xen/events.h b/include/xen/events.h
index c1717ca..deec8fa 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -71,6 +71,7 @@
  * GSIs are identity mapped; others are dynamically allocated as
  * usual. */
 int xen_allocate_pirq(unsigned gsi, int shareable, char *name);
+int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name);
 
 /* De-allocates the above mentioned physical interrupt. */
 int xen_destroy_irq(int irq);