tools headers UAPI: Sync the drm/drm.h with the kernel sources

tools headers UAPI: Sync the drm/drm.h with the kernel sources

Picking the changes from:

  c2d3a730069545f2 ("drm/syncobj: Extend EXPORT_SYNC_FILE for timeline syncobjs")

Silencing these perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/uapi/drm/drm.h include/uapi/drm/drm.h

No changes in tooling as these are just C comment documentation changes:

  $ tools/perf/trace/beauty/drm_ioctl.sh > before
  $ cp include/uapi/drm/drm.h tools/include/uapi/drm/drm.h
  $ tools/perf/trace/beauty/drm_ioctl.sh > after
  $ diff -u before after
  $

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rob Clark <robin.clark@oss.qualcomm.com>
Link: https://lore.kernel.org/r/aErtHs3T2hdPjjHx@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>