drm/bridge: optimize the 4K setting for LT9611

There is display corruption in 4K setup of LT9611 due to
the synchronization issue of dual DSI ports. Optimize the
LT9611 setting to address it.

CRs-Fixed: 2202161
Change-Id: I835d97394ebd61d626401e2d56f858d1d3e69005
Signed-off-by: Ray Zhang <rayz@codeaurora.org>