drm/msm: allow fractional value for panel jitter config

Panel jitter configuration causes early wakeup for
command mode panel with sde rscc hardware. Current
implementation allowed only integer value which
can go minimum 1% jitter and still causes early
wake up if panel can manage 0.5% or 0.8% jitter.
Moving to fractional value for panel jitter allows
longer mode-0/1 entry and increase the power saving
with sde rscc hardware.

Change-Id: Ie4c71b7c8d3f50db9db82d6035c713c3ccfc6ab8
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>