drm/msm/dpu: Drop unused members from HW structs

drm/msm/dpu: Drop unused members from HW structs

Some of these members were initialized while never read, while others
were not even assigned any pointer value at all.  Drop them to save some
space, and above all confusion when looking at or accidentally
dereferencing these members.

Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/533862/
Link: https://lore.kernel.org/r/20230418-dpu-drop-useless-for-lookup-v3-2-e8d869eea455@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>