use 'find' tree function

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
diff --git a/tree.h b/tree.h
index 7be3fc4..176dd23 100644
--- a/tree.h
+++ b/tree.h
@@ -45,3 +45,5 @@
 extern struct tree *tree_find(struct tree *tree, const char *name);
 
 extern int tree_for_each(struct tree *tree, tree_cb_t cb, void *data);
+
+extern int tree_for_each_parent(struct tree *tree, tree_cb_t cb, void *data);