[S390] Fix build errors (fallout from system.h disintegration)

Signed-off-by: Heiko Carstens <h.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 1581ea2..06264ae 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -50,6 +50,7 @@
 
 #include <asm/ipl.h>
 #include <asm/uaccess.h>
+#include <asm/facility.h>
 #include <asm/smp.h>
 #include <asm/mmu_context.h>
 #include <asm/cpcmd.h>