Bluetooth: btmrvl: support SCO routing to host interface

A vendor specific command is sent to firmware during
initialization to enable this feature.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Cathy Luo <cluo@marvell.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>