radeonsi: do Z-only or S-only HTILE clear using a compute shader doing RMW

radeonsi: do Z-only or S-only HTILE clear using a compute shader doing RMW

This adds a clear_buffer compute shader that does read-modify-write to
update a subset of bits in HTILE.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10003>