drm/msm: update sde rsc mode-2 entry/exit sequence

The sde rsc mode-2 entry/exit sequence needs update
for clk and vid state. A primary display (command mode
panel) may not be active when rsc is in clk state and
may not be configured to generate the vsync. It needs
different sequence because display is not active
and vsync is not configured.

Change-Id: If682f8f48bb337eccbcc5e6af1faf59bbc7cc8cb
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>