s390/time: always use stckf instead of stck if available

The store clock fast instruction saves a couple of instructions compared
to the store clock instruction. Always use stckf instead of stck if it
is available.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index 19902cd..7493efa 100644
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -517,7 +517,7 @@
 	int count, stop;
 	unsigned char state = 0;
 
-	q->timestamp = get_clock_fast();
+	q->timestamp = get_clock();
 
 	/*
 	 * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
@@ -788,7 +788,7 @@
 	int count, stop;
 	unsigned char state = 0;
 
-	q->timestamp = get_clock_fast();
+	q->timestamp = get_clock();
 
 	if (need_siga_sync(q))
 		if (((queue_type(q) != QDIO_IQDIO_QFMT) &&