drm/msm/dpu: simplify blend configuration

drm/msm/dpu: simplify blend configuration

Rewrite dpu_hw_ctl_setup_blendstage() to use static data configuration
rather than using a switch-case. This simplifies adding support for new
pipes.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550
Patchwork: https://patchwork.freedesktop.org/patch/518485/
Link: https://lore.kernel.org/r/20230116063316.728496-3-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>