drm/vram: switch to gem vma offset manager

Pass gem vma_offset_manager to ttm_bo_device_init(), so ttm uses it
instead of its own embedded struct. This makes some gem functions
(specifically drm_gem_object_lookup) work on ttm objects.

Signed-off-by: Gerd Hoffmann <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Acked-by: Thomas Zimmermann <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_vram_mm_helper.c

···
 
 	ret = ttm_bo_device_init(&vmm->bdev, &bo_driver,
 				 dev->anon_inode->i_mapping,
-				 NULL,
+				 dev->vma_offset_manager,
 				 true);
 	if (ret)
 		return ret;