tools include uapi: Grab copies of stat.h and fcntl.h

We will need it to build tools/perf/trace/beauty/statx.h.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-nin41ve2fa63lrfbdr6x57yr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>