Bluetooth: BAP: Add cc len check for BT_HCI_CODING_FORMAT_TRANSPARENT

When using BT_HCI_CODING_FORMAT_TRANSPARENT as the codec_id, the
codec configuration (cc) len sent to the controller shall be 0.

Since this goes for all devices, we ensure that we don't
send invalid codec ID and cc data over air.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>