power_supply: Populate supplied_from hierarchy from the device tree

With this patch the power_supply_core will try to populate supplied_from
hierarchy from the device tree.

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index c1cbd5e..3828cef 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -173,6 +173,9 @@
 
 	char **supplied_from;
 	size_t num_supplies;
+#ifdef CONFIG_OF
+	struct device_node *of_node;
+#endif
 
 	int (*get_property)(struct power_supply *psy,
 			    enum power_supply_property psp,