greybus: connection: add helper to create control connections

Add dedicated helper to create control connections.

This will allow us to simplify the generic (dynamic) interface.

Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
diff --git a/drivers/staging/greybus/connection.h b/drivers/staging/greybus/connection.h
index 562bd2b4..cd4a093 100644
--- a/drivers/staging/greybus/connection.h
+++ b/drivers/staging/greybus/connection.h
@@ -57,6 +57,7 @@
 
 struct gb_connection *gb_connection_create_static(struct gb_host_device *hd,
 				u16 hd_cport_id);
+struct gb_connection *gb_connection_create_control(struct gb_interface *intf);
 struct gb_connection *gb_connection_create_dynamic(struct gb_interface *intf,
 				struct gb_bundle *bundle, u16 cport_id,
 				u8 protocol_id);