[S390] cpu topology support for s390.

Add s390 backend so we can give the scheduler some hints about the
cpu topology.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/arch/s390/defconfig b/arch/s390/defconfig
index 62f6b5a..dcc3ec2 100644
--- a/arch/s390/defconfig
+++ b/arch/s390/defconfig
@@ -3,6 +3,7 @@
 # Linux kernel version: 2.6.25-rc4
 # Wed Mar  5 11:22:59 2008
 #
+CONFIG_SCHED_MC=y
 CONFIG_MMU=y
 CONFIG_ZONE_DMA=y
 CONFIG_LOCKDEP_SUPPORT=y