Add dummy audiodev backend driver for soundcard

[yanan-fu]

ID: 1763

Signed-off-by: Yanan Fu [email protected]

[yanan-fu]

QEMU 8.2 command line when run test with soundcards = hda-duplex :

[stdlog] 2024-03-13 01:17:29,511 avocado.utils.process process          L0657 INFO | Running 'rpm -qa | grep -E 'qemu-kvm(-(rhev|ma|core))?-[0-9]+\.' | head -n 1'
[stdlog] 2024-03-13 01:17:30,142 avocado.utils.process process          L0473 DEBUG| [stdout] qemu-kvm-core-8.2.0-6.el9.x86_64
...
[stdlog]     -device '{"driver": "intel-hda", "bus": "pcie-pci-bridge-0", "addr": "0x1"}' \
[stdlog]     -audiodev '{"id":"audiodev1","driver":"none"}' \
[stdlog]     -device '{"audiodev": "audiodev1", "driver": "hda-duplex"}' \