[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/Kconfig b/arch/s390/Kconfig
index 1831833..17cbc25 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -3,6 +3,10 @@
 # see Documentation/kbuild/kconfig-language.txt.
 #
 
+config SCHED_MC
+	def_bool y
+	depends on SMP
+
 config MMU
 	def_bool y