drm/msm/sde: move topology name reset to release resources

Simplify the clearing of the topology name by moving it directly
to the release resources call.

Change-Id: If1926372b276f01f64138691b805493d1894951a
Signed-off-by: Lloyd Atkinson <latkinso@codeaurora.org>
Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>