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>
diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index 3ff4dc9..7bf9a10 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -699,6 +699,7 @@
 	.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)