dm: core: add ofnode_for_each_compatible_node()

Add a helper to iterate over all nodes with a given compatible string.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index 6a714d0..0f680e5 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -1010,6 +1010,30 @@
 	     node = ofnode_next_subnode(node))
 
 /**
+ * ofnode_for_each_compatible_node() - iterate over all nodes with a given
+ *				       compatible string
+ *
+ * @node:       child node (ofnode, lvalue)
+ * @compat:     compatible string to match
+ *
+ * This is a wrapper around a for loop and is used like so:
+ *
+ *	ofnode node;
+ *
+ *	ofnode_for_each_compatible_node(node, parent, compatible) {
+ *		Use node
+ *		...
+ *	}
+ *
+ * Note that this is implemented as a macro and @node is used as
+ * iterator in the loop.
+ */
+#define ofnode_for_each_compatible_node(node, compat) \
+	for (node = ofnode_by_compatible(ofnode_null(), compat); \
+	     ofnode_valid(node); \
+	     node = ofnode_by_compatible(node, compat))
+
+/**
  * ofnode_get_child_count() - get the child count of a ofnode
  *
  * @node: valid node to get its child count