msm: mdss: move used pipes to cleanup list on overlay free

Avoid moving pipes to destroy list during overlay free based on
the pipe play count as it might not give the actual information.
The play count is set to 0 for all new or config changed pipes
during the validate call. And if we get a fb_release_all request
right after the validate, it would indicate an inconsistent state
for the play count. Instead, move the used pipes to cleanup list,
so that the NULL kickoff would handle the pipes to be unstaged
and destroyed.

Change-Id: I0026d512e92d0d59962ee8114873f7804a31c018
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>