drm/ttm/memcg/lru: enable memcg tracking for ttm, xe and amdgpu driver (part 2).

[Dave Airlie <airlied@gmail.com>]

I committed the vmstat counters and list lru changes, and they are now in tree.

This is the remainder of this series. Intel have expressed interest in getting
this landed for xe, we can drop the amdgpu changes for now if they can't get
across the line.

I've dropped all previous acks/reviews.

This series adds the memcg counters for GPU active and GPU reclaim to align
with the two global vmstats. It adds an accounting flag to TTM alloc/populate,
and enables memcg tracking and shrinker support in TTM.

Then it adds amdgpu and xe support.

I think for this to land, Christian holds the main objection which I still fail
to fully understand beyond it doesn't solve all the problems we ever have had
with cgroups and drm, so we shouldn't even bother, and maybe we could do it at
the object level, and integrated with dmem, and android cross process accounting,
but I still feel this is a good baseline.

I think this is the right layer to hook this into TTM, where we allocate memory
and I think accounting for this memory in a proper way should be done.

Intel folks (Thomas/Maarten) please review and express concerns as well.

Regards,
Dave.