drm/msm/dpu: dpu_hw_dsc.h: fix all kernel-doc warnings

drm/msm/dpu: dpu_hw_dsc.h: fix all kernel-doc warnings

Correct or add kernel-doc comments to eliminate all warnings:

Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:23 Incorrect use of
 kernel-doc format: * dsc_disable - disable dsc
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:29 Incorrect use of
 kernel-doc format: * dsc_config - configures dsc encoder
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:41 Incorrect use of
 kernel-doc format: * dsc_config_thresh - programs panel thresholds
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:50 struct member
 'dsc_disable' not described in 'dpu_hw_dsc_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:50 struct member
 'dsc_config' not described in 'dpu_hw_dsc_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:50 struct member
 'dsc_config_thresh' not described in 'dpu_hw_dsc_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_dsc.h:50 struct member
 'dsc_bind_pingpong_blk' not described in 'dpu_hw_dsc_ops'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/695658/
Link: https://lore.kernel.org/r/20251219184638.1813181-7-rdunlap@infradead.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>