drm/msm/sde: check for ppsplit topology from current state

During pm suspend-resume cases, topology is reset and ppsplit
flag is set to false based on previous connector state. This
leads to incorrect interface config resulting in pptimeout.
Made changes to update the ppsplit flag based on current
connector state to avoid this.

Change-Id: Id42313036eda98e5109083b0d57a778f1262f3fd
Signed-off-by: Shubhashree Dhar <dhar@codeaurora.org>