display hardware clock will not unprepare when
crtc is disable, until crtc is destroyed.
with this patch, hard clock will disable and unprepare
at the same time.
Signed-off-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: CK Hu <ck.hu@mediatek.com>