[POWERPC] Add an optional device_node pointer to the irq_host

The majority of irq_host implementations (3 out of 4) are associated
with a device_node, and need to stash it somewhere. Rather than having
it somewhere different for each host, add an optional device_node pointer
to the irq_host structure.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index 87cd68051..999f5e1 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -384,7 +384,7 @@
 	/*
 	 * Allocate an irq host
 	 */
-	pmac_pic_host = irq_alloc_host(IRQ_HOST_MAP_LINEAR, max_irqs,
+	pmac_pic_host = irq_alloc_host(master, IRQ_HOST_MAP_LINEAR, max_irqs,
 				       &pmac_pic_host_ops,
 				       max_irqs);
 	BUG_ON(pmac_pic_host == NULL);