tools headers uapi: Sync prctl.h with the kernel sources

To get the changes in ba830885 ("arm64: add prctl control for
resetting ptrauth keys"), that introduce a prctl with a name that needs
to be catch by the prctl cmd table generator, which will be done in the
next cset.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kristina Martsenko <kristina.martsenko@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/n/tip-a1pahzc8lci0ey1fjvv1chdm@git.kernel.org


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