greybus: hd: add cport_shutdown callback

Add a host-device cport_shutdown callback which will be called as part
of the new connection tear-down sequence for offloaded connection in
order to do a cport_shutdown operation on behalf of the AP.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Sandeep Patil <sspatil@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/hd.h

@@ -25,6 +25,8 @@ struct gb_hd_driver {
 	int (*cport_connected)(struct gb_host_device *hd, u16 cport_id);
 	int (*cport_flush)(struct gb_host_device *hd, u16 cport_id);
 	int (*cport_ping)(struct gb_host_device *hd, u16 cport_id);
+	int (*cport_shutdown)(struct gb_host_device *hd, u16 cport_id,
+				u8 phase, unsigned int timeout);
 	int (*cport_quiesce)(struct gb_host_device *hd, u16 cport_id,
 				size_t peer_space, unsigned int timeout);
 	int (*cport_clear)(struct gb_host_device *hd, u16 cport_id);