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 <[e-mail]>
Reviewed-by: Viresh Kumar <[e-mail]>
Acked-by: Sandeep Patil <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/greybus/hd.h

···
 	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);