tools headers UAPI: Sync sched.h with the kernel

To get the changes in:

  0acefef5 ("Merge tag 'threads-v5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux")
  49cb2fc4 ("fork: extend clone3() to support setting a PID")
  fa729c4d ("clone3: validate stack arguments")
  b612e5df

 ("clone3: add CLONE_CLEAR_SIGHAND")

This file gets rebuilt, but no changes ensues:

   CC       /tmp/build/perf/trace/beauty/clone.o

This addresses this perf build warning:

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

The CLONE_CLEAR_SIGHAND one will be used in tools/perf/trace/beauty/clone.c
in a followup patch to show that string when this bit is set in the
syscall arg. Keeping a copy of this file allows us to build this in
older systems and have the binary support printing that flag whenever
that system gets its kernel updated to one where this feature is
present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Adrian Reber <areber@redhat.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-nprqsvvzbhzoy64cbvos6c5b@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>