drm/msm/dpu: wire up MSM8998's DSPP blocks

The commit adding msm8998 support didn't added msm8998's DSPP blocks
configuration, but did not use them in msm8998_cfg_init(). Wire them up
to be used for display post processing.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 94391a14

 ("drm/msm/dpu1: Add MSM8998 to hw catalog")
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Cc: Jami Kettunen <jami.kettunen@somainline.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/475544/
Link: https://lore.kernel.org/r/20220222031948.228727-1-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>