drm/msm/dpu: support plane splitting in quad-pipe case

drm/msm/dpu: support plane splitting in quad-pipe case

The content of every half of screen is sent out via one interface in
dual-DSI case. The content for every interface is blended by a LM
pair in quad-pipe case, thus a LM pair should not blend any content
that cross the half of screen in this case. Clip plane into pipes per
left and right half screen ROI if topology is quad pipe case.

The clipped rectangle on every half of screen is futher handled by two
pipes if its width exceeds a limit for a single pipe.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/675416/
Link: https://lore.kernel.org/r/20250918-v6-16-rc2-quad-pipe-upstream-4-v16-9-ff6232e3472f@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>