tools include UAPI: Sync linux/mount.h copy with the kernel sources

To pick the changes from:

  6ac39281 ("fs: allow to mount beneath top mount")

That, after a fix to the move_mount_flags.sh script, harvests the new
MOVE_MOUNT_BENEATH move_mount flag:

  $ tools/perf/trace/beauty/move_mount_flags.sh > before
  $ cp include/uapi/linux/mount.h tools/include/uapi/linux/mount.h
  $ tools/perf/trace/beauty/move_mount_flags.sh > after
  $
  $ diff -u before after
  --- before	2023-07-11 12:38:49.244886707 -0300
  +++ after	2023-07-11 12:51:15.125255940 -0300
  @@ -6,4 +6,5 @@
   	[ilog2(0x00000020) + 1] = "T_AUTOMOUNTS",
   	[ilog2(0x00000040) + 1] = "T_EMPTY_PATH",
   	[ilog2(0x00000100) + 1] = "SET_GROUP",
  +	[ilog2(0x00000200) + 1] = "BENEATH",
   };
  $

That will then be properly decoded when used in tools like:

  # perf trace -e move_mount

This addresses this perf build warning:

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

Cc: Christian Brauner <brauner@kernel.org>
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>
Link: https://lore.kernel.org/lkml/ZK17kifP%2FiYl+Hcc@kernel.org/


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>