Bluetooth: Fix CID initialization for fixed channels

Fixed channels have the same source and destination CID. Ensure that the
values get properly initialized when receiving incoming connections and
deriving values from the parent socket.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --cc net/bluetooth/l2cap_core.c
Simple merge

diff --cc net/bluetooth/l2cap_sock.c
Simple merge