tools headers: Synchronize uapi/linux/sched.h

To get the tools copy updated with the changes in 34be3930
("sched/deadline: Implement "runtime overrun signal" support"), that
cause no effect on the tools, will be used when we start copying the
sched_attr struct argument to the sched_get/setattr syscalls.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-8rododhs87x8hv9k83qcdtne@git.kernel.org


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