of: add of_parse_phandle() helper for parsing phandle properties

of_parse_phandle() is a helper function to read and parse a phandle
property and return a pointer to the resulting device_node.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/of.h b/include/linux/of.h
index 6a7efa2..7be2d10 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -77,6 +77,9 @@
 extern const struct of_device_id *of_match_node(
 	const struct of_device_id *matches, const struct device_node *node);
 extern int of_modalias_node(struct device_node *node, char *modalias, int len);
+extern struct device_node *of_parse_phandle(struct device_node *np,
+					    const char *phandle_name,
+					    int index);
 extern int of_parse_phandles_with_args(struct device_node *np,
 	const char *list_name, const char *cells_name, int index,
 	struct device_node **out_node, const void **out_args);