drm/msm/dpu: adjust data width for widen bus case

drm/msm/dpu: adjust data width for widen bus case

data is valid for only half the active window if widebus
is enabled

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-QRD
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/596229/
Link: https://lore.kernel.org/r/20240530-msm-drm-dsc-dsi-video-upstream-4-v6-2-2ab1d334c657@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>