of/reconfig: Add of_reconfig_get_state_change() of notifier helper.

Introduce of_reconfig_get_state_change() which allows an of notifier
to query about device state changes.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/include/linux/of.h b/include/linux/of.h
index 27635c8..8e3a264 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -327,6 +327,7 @@
 extern int of_reconfig_notifier_register(struct notifier_block *);
 extern int of_reconfig_notifier_unregister(struct notifier_block *);
 extern int of_reconfig_notify(unsigned long, void *);
+extern int of_reconfig_get_state_change(unsigned long action, void *arg);
 
 extern int of_attach_node(struct device_node *);
 extern int of_detach_node(struct device_node *);
@@ -887,6 +888,12 @@
 	struct list_head entries;
 };
 
+enum of_reconfig_change {
+	OF_RECONFIG_NO_CHANGE = 0,
+	OF_RECONFIG_CHANGE_ADD,
+	OF_RECONFIG_CHANGE_REMOVE,
+};
+
 #ifdef CONFIG_OF_DYNAMIC
 extern void of_changeset_init(struct of_changeset *ocs);
 extern void of_changeset_destroy(struct of_changeset *ocs);