drm/msm/dpu: Move DPU_SSPP_QOS_8LVL bit to SDM845 and SC7180 masks

Not all DPU versions that are supported in this driver are supposed
to have a 8-Levels VIG QoS setting.
Move this flag to SDM845 and SC7180 specific masks.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>