pmb.qemu.run: replace removed -soundhw option

In the QEMU 7.1 release the deprecated -soundhw option was removed.
Replace it with -audio so we can have audio working again in QEMU.

See also https://www.qemu.org/docs/master/about/removed-features.html



Reviewed-by: Oliver Smith <ollieparanoid@postmarketos.org>
Link: https://lists.sr.ht/~postmarketos/pmbootstrap-devel/%3C20230605102320.739043-1-luca@z3ntu.xyz%3E