drm/ttm: make eviction decision a driver callback v2

This way the driver can decide if it is valuable to evict a BO or not.

The current implementation is added as default to all existing drivers.

v2: fix some typos found during internal testing

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1561,6 +1561,7 @@ struct ttm_bo_driver nouveau_bo_driver = {
 	.ttm_tt_unpopulate = &nouveau_ttm_tt_unpopulate,
 	.invalidate_caches = nouveau_bo_invalidate_caches,
 	.init_mem_type = nouveau_bo_init_mem_type,
+	.eviction_valuable = ttm_bo_eviction_valuable,
 	.evict_flags = nouveau_bo_evict_flags,
 	.move_notify = nouveau_bo_move_ntfy,
 	.move = nouveau_bo_move,