s390/time: rename tod clock access functions

Fix name clash with some common code device drivers and add "tod"
to all tod clock access function names.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 7918fbe..504175e 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -293,7 +293,7 @@
 			 * retry this instruction.
 			 */
 			spin_lock(&ipd_lock);
-			tmp = get_clock();
+			tmp = get_tod_clock();
 			if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
 				ipd_count++;
 			else