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/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 0b54a91..2e58f47 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -21,6 +21,7 @@
 #include <asm/chpid.h>
 #include <asm/sclp.h>
 #include <asm/setup.h>
+#include <asm/ctl_reg.h>
 
 #include "sclp.h"