drm/msm/sde: fix sde rsc state machine

Add clk state in sde rsc state machine. SDE
power handle and v4l2 driver must request for
this new clk state anytime their clients
wants to access the display hardware. A clk
state request avoids mdss gdsc power collapse.
This patch also fixes the sde rsc state machine
for other cases like vid, cmd mode.

Change-Id: I3c47e28e81e2f59bd9191925e3130c124b8da67e
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>