[PATCH 0/4] Add Panthor compute-shader test

[Daniel Stone <daniels@collabora.com>]

Hi,
This series adds a test to the Panthor suite to exercise a simple
compute shader. Whilst the existing group_submit test does validate that
we're able to execute CSF commands, it doesn't validate that we can use
this to actually run any shaders. This series should help as minimal
bringup and validation, inspired by a platform which was able to pass
group_submit just fine, but would immediately wedge the firmware when
trying to run a compute-shader test.

I don't plan to extend this much further - at least not with more
complex GPU command types or shader ISA, since that would require a lot
more divergent per-arch code to deal with changes in descriptor tables
and commands - but it does ensure that we can actually schedule and
execute jobs on a GPU.

Tested on v10 (RK3588), v13 (MT8196), and v14 (Lumex CSS FVP).

Cheers,
Daniel