drm/vram-helper: remove populate/unpopulate

The default path for populate/unpopulate is already this.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200804025632.3868079-8-airlied@gmail.com

drivers/gpu/drm/drm_gem_vram_helper.c

@@ -1061,8 +1061,6 @@ static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev,
 
 static struct ttm_bo_driver bo_driver = {
 	.ttm_tt_create = bo_driver_ttm_tt_create,
-	.ttm_tt_populate = ttm_pool_populate,
-	.ttm_tt_unpopulate = ttm_pool_unpopulate,
 	.eviction_valuable = ttm_bo_eviction_valuable,
 	.evict_flags = bo_driver_evict_flags,
 	.move_notify = bo_driver_move_notify,