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/virtio/virtgpu_ttm.c

@@ -425,6 +425,7 @@ static struct ttm_bo_driver virtio_gpu_bo_driver = {
 	.ttm_tt_unpopulate = &virtio_gpu_ttm_tt_unpopulate,
 	.invalidate_caches = &virtio_gpu_invalidate_caches,
 	.init_mem_type = &virtio_gpu_init_mem_type,
+	.eviction_valuable = ttm_bo_eviction_valuable,
 	.evict_flags = &virtio_gpu_evict_flags,
 	.move = &virtio_gpu_bo_move,
 	.verify_access = &virtio_gpu_verify_access,