disp: msm: sde: dump clock state before entering suspend

Add debug capability to dump clocks before entering pm suspend.
This will help debug invalid register access when clocks are off
during adversarial test cases.

Change-Id: I80d19b751a3b9a1de0cc64699a21a1852d614ced
Signed-off-by: Amine Najahi <anajahi@codeaurora.org>