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.

For non-virtual-plane case, there is always one stage config to serve
a LM or LM pair. So the clipping does not occur when interating stages
in this case. The plane is mapped to 2 pipes only when width or clock
rate exceeds hardware constrain within stage check.

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/711324/
Link: https://lore.kernel.org/r/20260312-msm-next-quad-pipe-split-v19-3-4ffa2b06c996@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>