tools headers: Sync the various kvm.h header copies

For powerpc, s390, x86 and the main uapi linux/kvm.h header, none of
them entail changes in tooling.

Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-avn7iy8f4tcm2y40sbsdk31m@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>