drm/msm/dpu: use right setup_blend_config for sm8150 and sm8250

All DPU versions starting from 4.0 use the sdm845 version, so check for
that instead of checking each version individually. This chooses the right
function for sm8150 and sm8250.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Signed-off-by: Rob Clark <robdclark@chromium.org>