Bluetooth: L2CAP: Fix setting chan src info before adding PSM/CID

At least the l2cap_add_psm() routine depends on the source address
type being properly set to know what auto-allocation ranges to use, so
the assignment to l2cap_chan needs to happen before this.

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