msm: mdss: force HW reprogram when ROI changes mixer layout

Current driver has various optimizations to skip pipe reprogramming if
certain layer parameters are not changed. However if mixer layout changes
then we need to reprogram all the staged pipes on that mixer. This
scenario can happen when partial update is enabled on a topology with
split layer mixers. Add a logic to find if the mixer layout is changing
between two consecutive updates and if it does, force reprogramming of
all the staged pipes.

CRs-fixed: 946164
Change-Id: I16caa4bb8b9587b804d6543d0bd340df970784ba
Signed-off-by: Ujwal Patel <ujwalp@codeaurora.org>