[S390] asm-s390/posix_types.h: drop __USE_ALL usage

Bring s390 in line with all the other ports.  Not sure how s390 missed
this change as all the other arches were being updated ...

CC: Heiko Carstens <heiko.carstens@de.ibm.com>
CC: linux390@de.ibm.com
CC: linux-s390@vger.kernel.org
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>