ARM: dts: msm: Optimize HX8399 panel initialization code

When do panel suspend/resume stress test, panel will
flicker for about 1~2 minutes occasionally. Modified
some initialization parameters for the panel.

Change-Id: I8cbf6556e6f40eb8be5ee80bef141ec5a2833efb
Signed-off-by: Yuan Zhao <yzhao@codeaurora.org>