[POWERPC] Fix new interrupt code (MPIC detection)

As the code comment already says, the Maple device-tree is incorrect here;
make the Linux code detect the correct thing, too.
Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/maple/setup.c

@@ -221,6 +221,13 @@ static void __init maple_init_IRQ(void)
 	 * in Maple device-tree where the type of the controller is
 	 * open-pic and not interrupt-controller
 	 */
+
+	for_each_node_by_type(np, "interrupt-controller")
+		if (device_is_compatible(np, "open-pic")) {
+			mpic_node = np;
+			break;
+		}
+	if (mpic_node == NULL)
 		for_each_node_by_type(np, "open-pic") {
 			mpic_node = np;
 			break;