sched, numa, mm, s390/thp: Add pmd_mknotpresent()

sched, numa, mm, s390/thp: Add pmd_mknotpresent()

We'd like to make use of pmd_mknotpresent() in mm/, but
not all architectures have it. This patch adds the s390
version.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Link: http://lkml.kernel.org/r/20121028131014.GA10754@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>