drm/msm/dpu: add support for wide planes

It is possible to use multirect feature and split source to use the SSPP
to output two consecutive rectangles. This commit brings in this
capability to support wider screen resolutions.

Tested-by: Abhinav Kumar <quic_abhinavk@quicinc.com> # sc7280
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/527358/
Link: https://lore.kernel.org/r/20230316161653.4106395-28-dmitry.baryshkov@linaro.org


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>