Pretty straightforward update. I rebased all the patches, and some of the linux-4.9 changes had been done upstream. I had to add an empty amdkcl_io_init() to fix a missing symbol on 4.9 (https://github.com/NixOS/nixpkgs/pull/24749/files#diff-8d4e1533a818ba8e21cc062ff8de7e4fR20).

@ninegua @plchldr Since you were involved in the last update (#22241).

I'm mostly using mesa these days, but if you're interested in this and you want to try it out, let me know how it goes.

@vcunat Since you merged the last one. I don't see a lot of interest in testing this, which is understandable given how solid mesa is these days.