drm/msm/sde: move release fence to crtc frame done event for cmd mode

Currently, crtc output_fence is released during commit_complete.
Release the fence early in frame_done crtc event for cmd mode
panels to increase performance, as the buffers are no longer
required after PPDONE.

Change-Id: Ie711adeee20d10530508bd11e2fa04a599e1f9c1
Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>