device property: Add support for remote endpoints

This follows DT implementation of of_graph_* APIs but we call them
fwnode_graph_* instead. For DT nodes the existing of_graph_* implementation
will be used. For ACPI we use the new ACPI graph implementation instead.

Signed-off-by: Mika Westerberg <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
diff --git a/include/linux/property.h b/include/linux/property.h
index 514b195..8d7809c 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -268,4 +268,13 @@ int device_get_phy_mode(struct device *dev);
 
 void *device_get_mac_address(struct device *dev, char *addr, int alen);
 
+struct fwnode_handle *fwnode_graph_get_next_endpoint(
+	struct fwnode_handle *fwnode, struct fwnode_handle *prev);
+struct fwnode_handle *fwnode_graph_get_remote_port_parent(
+	struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_graph_get_remote_port(
+	struct fwnode_handle *fwnode);
+struct fwnode_handle *fwnode_graph_get_remote_endpoint(
+	struct fwnode_handle *fwnode);
+
 #endif /* _LINUX_PROPERTY_H_ */