https://bugs.freedesktop.org/show_bug.cgi?id=103404
--- Comment #12 from randomsalad@gmail.com --- I can confirm the patch works, and was the only thing missing to get HDMI audio working on my Vega card. I can confirm it works for atleast 5.1 and 2.0 channel audio as those are the only options available to me with my Receiver, though this was just what I needed.
Thanks!