Bluetooth: Don't send connection parameters without identity address

If we don't have an identity address for connection parameters it
doesn't really make sense to send them to user space. Instead just
ignore them for now. Later we can add support for sending them when we
eventually get the identity through pairing.

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