disp: msm: sde: fix rounded corner region partial update logic

Currently driver determines the RC regions to enable/disable by
combining partial update ROI information and RC mask flag field.
This lead to invalid outcome when a transition from partial update
frame to full update frame occurs.

This change modifies the enable/disable logic to only use RC mask flags
from usermode client. It also adds the non-intersecting RC and ROI use
case to global use case table and fix the y_start programming when ROI
is only in bottom region.

Change-Id: Ie05c5ecba6bd0323d1c8fd6949e12cec1f56b477
Signed-off-by: Amine Najahi <anajahi@codeaurora.org>