drm/msm/dpu: Wire up DSC mask for active CTL configuration

drm/msm/dpu: Wire up DSC mask for active CTL configuration

Active CTLs have to configure what DSC block(s) have to be enabled, and
what DSC block(s) have to be flushed; this value was initialized to zero
resulting in the necessary register writes to never happen (or would
write zero otherwise).  This seems to have gotten lost in the DSC v4->v5
series while refactoring how the combination with merge_3d was handled.

Fixes: 58dca9810749 ("drm/msm/disp/dpu1: Add support for DSC in encoder")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/515693/
Link: https://lore.kernel.org/r/20221221231943.1961117-2-marijn.suijten@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>