openrisc: use for_each_of_cpu_node iterator

Use the for_each_of_cpu_node iterator to iterate over cpu nodes. This
has the side effect of defaulting to iterating using "cpu" node names in
preference to the deprecated (for FDT) device_type == "cpu".

This also fixes a leaked reference for cpus node.

Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
Acked-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

arch/openrisc/kernel/setup.c

@@ -158,9 +158,8 @@ static struct device_node *setup_find_cpu_node(int cpu)
 {
 	u32 hwid;
 	struct device_node *cpun;
-	struct device_node *cpus = of_find_node_by_path("/cpus");
 
-	for_each_available_child_of_node(cpus, cpun) {
+	for_each_of_cpu_node(cpun) {
 		if (of_property_read_u32(cpun, "reg", &hwid))
 			continue;
 		if (hwid == cpu)