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

drm/msm/dpu: dpu_hw_pingpong.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_pingpong.h:36 Cannot find
 identifier on line: *
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:46 Incorrect use
 of kernel-doc format: * enables vysnc generation and sets up init value of
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:53 Incorrect use
 of kernel-doc format: * disables tear check block
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:58 Incorrect use
 of kernel-doc format: * read, modify, write to either set or clear
 listening to external TE
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:65 Incorrect use
 of kernel-doc format: * Obtain current vertical line counter
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:70 Incorrect use
 of kernel-doc format: * Disable autorefresh if enabled
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:75 Incorrect use
 of kernel-doc format: * Setup dither matix for pingpong block
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:80 Incorrect use
 of kernel-doc format: * Enable DSC
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:85 Incorrect use
 of kernel-doc format: * Disable DSC
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:90 Incorrect use
 of kernel-doc format: * Setup DSC
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:93 struct member
 'connect_external_te' not described in 'dpu_hw_pingpong_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:93 struct member
 'disable_autorefresh' not described in 'dpu_hw_pingpong_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:93 struct member
 'enable_dsc' not described in 'dpu_hw_pingpong_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:93 struct member
 'disable_dsc' not described in 'dpu_hw_pingpong_ops'
Warning: drivers/gpu/drm/msm/disp/dpu1/dpu_hw_pingpong.h:93 struct member
 'setup_dsc' not described in 'dpu_hw_pingpong_ops'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/695659/
Link: https://lore.kernel.org/r/20251219184638.1813181-12-rdunlap@infradead.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>