tools headers UAPI: Sync drm/i915_drm.h with the kernel sources

tools headers UAPI: Sync drm/i915_drm.h with the kernel sources

To pick the changes in:

  13149e8bafc46572 ("drm/i915: add syncobj timeline support")
  cda9edd02425d790 ("drm/i915: introduce a mechanism to extend execbuf2")

That don't result in any changes in tooling, just silences this perf
build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/drm/i915_drm.h' differs from latest version at 'include/uapi/drm/i915_drm.h'
  diff -u tools/include/uapi/drm/i915_drm.h include/uapi/drm/i915_drm.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>