of: Introduce of_phandle_iterator_args()

This helper function can be used to copy the arguments of a
phandle to an array.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Rob Herring <robh@kernel.org>
diff --git a/include/linux/of.h b/include/linux/of.h
index b0b8071..71e1c35 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -359,6 +359,9 @@
 				    int cell_count);
 
 extern int of_phandle_iterator_next(struct of_phandle_iterator *it);
+extern int of_phandle_iterator_args(struct of_phandle_iterator *it,
+				    uint32_t *args,
+				    int size);
 
 extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align));
 extern int of_alias_get_id(struct device_node *np, const char *stem);
@@ -648,6 +651,13 @@
 	return -ENOSYS;
 }
 
+static inline int of_phandle_iterator_args(struct of_phandle_iterator *it,
+					   uint32_t *args,
+					   int size)
+{
+	return 0;
+}
+
 static inline int of_alias_get_id(struct device_node *np, const char *stem)
 {
 	return -ENOSYS;