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/drivers/s390/char/sclp_sdias.c b/drivers/s390/char/sclp_sdias.c
index 69e6c50..50f7115 100644
--- a/drivers/s390/char/sclp_sdias.c
+++ b/drivers/s390/char/sclp_sdias.c
@@ -211,7 +211,7 @@
 	sccb.evbuf.event_qual = EQ_STORE_DATA;
 	sccb.evbuf.data_id = DI_FCP_DUMP;
 	sccb.evbuf.event_id = 4712;
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
 	sccb.evbuf.asa_size = ASA_SIZE_64;
 #else
 	sccb.evbuf.asa_size = ASA_SIZE_32;