msm_fb: display: decrease mdp_timer_duration

mdp_timer_duration decides when both mdp and vsync clocks
be turned off after last screen updated. Decrease mdp_timer_duration
to 20ms to have clocks be turned off sooner.

CRs-fixed: 315271
Change-Id: Icf7f0a64ab38dd5184a12242cfc190efa31016a9
Signed-off-by: kuogee hsieh <khsieh@codeaurora.org>
3 files changed