audio: allow optional audio drivers.

For those audio drivers which can be probed (sdl, alsa, pulse) add a
try-$name variants.  Unlike the variants without try- prefix they will
not error out on probe failure, the driver will be dropped from the list
instead.  Mainly useful for the audio_drv_list default values.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20190124112055.547-3-kraxel@redhat.com
1 file changed