s390/headers: replace __s390x__ with CONFIG_64BIT where possible

Replace __s390x__ with CONFIG_64BIT in all places that are not exported
to userspace or guarded with #ifdef __KERNEL__.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/sfp-util.h b/arch/s390/include/asm/sfp-util.h
index ca3f881..5959bfb 100644
--- a/arch/s390/include/asm/sfp-util.h
+++ b/arch/s390/include/asm/sfp-util.h
@@ -51,7 +51,7 @@
 	wl = __wl;					\
 })
 
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
 #define udiv_qrnnd(q, r, n1, n0, d)			\
   do { unsigned long __n;				\
        unsigned int __r, __d;				\