Disintegrate asm/system.h for S390

Disintegrate asm/system.h for S390.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-s390@vger.kernel.org
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 1cb8427..7bb15fc 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -12,7 +12,7 @@
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/gfp.h>
-#include <asm/system.h>
+#include <asm/ctl_reg.h>
 
 /*
  * This function writes to kernel memory bypassing DAT and possible