drm/ttm: drop move notify around move.

The drivers now do this in the move callback.

move_notify is still needed in the destroy path.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201020010319.1692445-7-airlied@gmail.com