The tools/include/uapi/linux/mount.h file is mostly used for scrapping
defines into id->string tables, this is the only place were it is being
directly used, stop doing so.

Define MOUNT_ATTR_RELATIME and MOUNT_ATTR__ATIME if not available in the
system's headers.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>