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

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

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

Warning: drivers/gpu/drm/msm/msm_gpu.h:119 Incorrect use of kernel-doc
 format: * devfreq: devfreq instance
Warning: drivers/gpu/drm/msm/msm_gpu.h:125 Incorrect use of kernel-doc
 format: * idle_freq:
Warning: drivers/gpu/drm/msm/msm_gpu.h:136 Incorrect use of kernel-doc
 format: * boost_constraint:
Warning: drivers/gpu/drm/msm/msm_gpu.h:144 Incorrect use of kernel-doc
 format: * busy_cycles: Last busy counter value, for calculating elapsed
 busy
Warning: drivers/gpu/drm/msm/msm_gpu.h:156 Incorrect use of kernel-doc
 format: * idle_work:
Warning: drivers/gpu/drm/msm/msm_gpu.h:163 Incorrect use of kernel-doc
 format: * boost_work:
Warning: drivers/gpu/drm/msm/msm_gpu.h:170 struct member 'devfreq' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:170 struct member 'boost_freq' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'devfreq' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'lock' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'governor' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'we are
 continuing to sample busyness and * adjust frequency while the GPU is
 idle' not described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'boost_freq' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'busy_cycles'
 not described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'time' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'idle_time' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'idle_work' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'boost_work' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:172 struct member 'suspended' not
 described in 'msm_gpu_devfreq'
Warning: drivers/gpu/drm/msm/msm_gpu.h:472 No description found for
 return value of 'msm_context_is_vmbind'
Warning: drivers/gpu/drm/msm/msm_gpu.h:476 struct member 'ref' not
 described in 'msm_context'
Warning: drivers/gpu/drm/msm/msm_gpu.h:476 struct member 'elapsed_ns' not
 described in 'msm_context'
Warning: drivers/gpu/drm/msm/msm_gpu.h:492 expecting prototype for
 msm_context_is_vm_bind(). Prototype was for msm_context_is_vmbind()
 instead
Warning: drivers/gpu/drm/msm/msm_gpu.h:523 No description found for
 return value of 'msm_gpu_convert_priority'
Warning: drivers/gpu/drm/msm/msm_gpu.h:583 expecting prototype for
 struct msm_gpu_submitqueues. Prototype was for struct msm_gpu_submitqueue
 instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/695671/
Link: https://lore.kernel.org/r/20251219184638.1813181-19-rdunlap@infradead.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>