[klibc] sigsuspend: unbreak s390x

s390 does *not* work with RT syscalls, and s390x is distinguished
from s390 even if they share the same arch include directory

tested both on zelenka.debian.org

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>
Signed-off-by: maximilian attems <max@stro.at>
1 file changed