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 <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20190905070509.22407-3-kraxel@redhat.com