disp: msm: sde: use current crtc state during idle work scheduling

In the current code, previous crtc state is used to know
the idle timeout period and to schedule the idle notify
work. Due to this, notify work is not getting scheduled
in some cases even when idle timeout is specified. This
change uses current state for idle timeout period.

Change-Id: I3ff4df6a8edd6a5a20d2e19c3c27ebb221694ac1
Signed-off-by: Yashwanth <yvulapu@codeaurora.org>