[POWERPC] Remove old interface find_devices

Replace uses with of_find_node_by_name and for_each_node_by_name.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/powermac/backlight.c b/arch/powerpc/platforms/powermac/backlight.c
index 0dc8a45..d679964 100644
--- a/arch/powerpc/platforms/powermac/backlight.c
+++ b/arch/powerpc/platforms/powermac/backlight.c
@@ -56,13 +56,16 @@
 
 int pmac_has_backlight_type(const char *type)
 {
-	struct device_node* bk_node = find_devices("backlight");
+	struct device_node* bk_node = of_find_node_by_name(NULL, "backlight");
 
 	if (bk_node) {
 		const char *prop = of_get_property(bk_node,
 				"backlight-control", NULL);
-		if (prop && strncmp(prop, type, strlen(type)) == 0)
+		if (prop && strncmp(prop, type, strlen(type)) == 0) {
+			of_node_put(bk_node);
 			return 1;
+		}
+		of_node_put(bk_node);
 	}
 
 	return 0;