HSI: method to unregister clients from an hsi port

This exports a method to unregister all clients from
an hsi port.

Signed-off-by: Sebastian Reichel <sre@kernel.org>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Tested-By: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h
index 39bfd5b..5a9f121 100644
--- a/include/linux/hsi/hsi.h
+++ b/include/linux/hsi/hsi.h
@@ -282,6 +282,7 @@
 void hsi_put_controller(struct hsi_controller *hsi);
 int hsi_register_controller(struct hsi_controller *hsi);
 void hsi_unregister_controller(struct hsi_controller *hsi);
+void hsi_port_unregister_clients(struct hsi_port *port);
 
 static inline void hsi_controller_set_drvdata(struct hsi_controller *hsi,
 								void *data)