Bluetooth: Add chan->ops->defer()

When DEFER_SETUP is set defer() will trigger an authorization
request to the userspace.

l2cap_chan_no_defer() is meant to be used when one does not want to
support DEFER_SETUP (A2MP for example).

Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/a2mp.c

@@ -699,6 +699,7 @@ static struct l2cap_ops a2mp_chan_ops = {
 	.new_connection = l2cap_chan_no_new_connection,
 	.teardown = l2cap_chan_no_teardown,
 	.ready = l2cap_chan_no_ready,
+	.defer = l2cap_chan_no_defer,
 };
 
 static struct l2cap_chan *a2mp_chan_open(struct l2cap_conn *conn, bool locked)