[media] media: fix kernel-doc warnings in v4l2-dv-timings.h
Fix the following 'make htmldocs' warnings:
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'frame_height'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'hfreq'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'vsync'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'active_width'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'polarities'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'interlaced'
.//include/media/v4l2-dv-timings.h:147: warning: No description found for parameter 'fmt'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'frame_height'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'hfreq'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'vsync'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'polarities'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'interlaced'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'aspect'
.//include/media/v4l2-dv-timings.h:171: warning: No description found for parameter 'fmt'
.//include/media/v4l2-dv-timings.h:184: warning: No description found for parameter 'hor_landscape'
.//include/media/v4l2-dv-timings.h:184: warning: No description found for parameter 'vert_portrait'