drm/ttm: Remove two unused function declarations

Commit cd3a8a59 ("drm/ttm: remove ttm_bo_(un)lock_delayed_workqueue")
removed the implementations but not the declarations.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230809135839.13216-1-yuehaibing@huawei.comSigned-off-by: Christian König <christian.koenig@amd.com>

include/drm/ttm/ttm_bo.h

@@ -355,8 +355,6 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
 void ttm_bo_put(struct ttm_buffer_object *bo);
 void ttm_bo_set_bulk_move(struct ttm_buffer_object *bo,
 			  struct ttm_lru_bulk_move *bulk);
-int ttm_bo_lock_delayed_workqueue(struct ttm_device *bdev);
-void ttm_bo_unlock_delayed_workqueue(struct ttm_device *bdev, int resched);
 bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 			      const struct ttm_place *place);
 int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,