audio/adlib: remove limitation of one adlib card

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20170621043401.19842-3-hpoussin@reactos.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
