Bluetooth: SCO: Add support for 16 bits transparent voice setting

The voice setting is used by sco_connect() or sco_conn_defer_accept()
after being set by sco_sock_setsockopt().

The PCM part of the voice setting is used for offload mode through PCM
chipset port.
This commits add support for mSBC 16 bits offloading, i.e. audio data
not transported over HCI.

The BCM4349B1 supports 16 bits transparent data on its I2S port.
If BT_VOICE_TRANSPARENT is used when accepting a SCO connection, this
gives only garbage audio while using BT_VOICE_TRANSPARENT_16BIT gives
correct audio.
This has been tested with connection to iPhone 14 and Samsung S24.

Fixes: ad10b1a4 ("Bluetooth: Add Bluetooth socket voice option")
Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>