[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/sysdev/qe_lib/qe_ic.c b/arch/powerpc/sysdev/qe_lib/qe_ic.c
index 4d1dcb4..55e6f39 100644
--- a/arch/powerpc/sysdev/qe_lib/qe_ic.c
+++ b/arch/powerpc/sysdev/qe_lib/qe_ic.c
@@ -245,10 +245,8 @@
 
 static int qe_ic_host_match(struct irq_host *h, struct device_node *node)
 {
-	struct qe_ic *qe_ic = h->host_data;
-
 	/* Exact match, unless qe_ic node is NULL */
-	return qe_ic->of_node == NULL || qe_ic->of_node == node;
+	return h->of_node == NULL || h->of_node == node;
 }
 
 static int qe_ic_host_map(struct irq_host *h, unsigned int virq,
@@ -352,9 +350,8 @@
 		return;
 
 	memset(qe_ic, 0, sizeof(struct qe_ic));
-	qe_ic->of_node = of_node_get(node);
 
-	qe_ic->irqhost = irq_alloc_host(IRQ_HOST_MAP_LINEAR,
+	qe_ic->irqhost = irq_alloc_host(of_node_get(node), IRQ_HOST_MAP_LINEAR,
 					NR_QE_IC_INTS, &qe_ic_host_ops, 0);
 	if (qe_ic->irqhost == NULL) {
 		of_node_put(node);