Bluetooth: add support to notify using SCO air mode

notifying using HCI_NOTIFY_CONN_ADD for SCO connection is generic in
case of mSBC audio. To differntiate SCO air mode introducing
HCI_NOTIFY_ENABLE_SCO_CVSD and HCI_NOTIFY_ENABLE_SCO_TRANSP.

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