drm/ttm: move the LRU into resource handling v4

This way we finally fix the problem that new resource are
not immediately evict-able after allocation.

That has caused numerous problems including OOM on GDS handling
and not being able to use TTM as general resource manager.

v2: stop assuming in ttm_resource_fini that res->bo is still valid.
v3: cleanup kerneldoc, add more lockdep annotation
v4: consistently use res->num_pages

Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220321132601.2161-1-christian.koenig@amd.com