dm: rtc: Rename mktime() and reduce the number of parameters

Most callers unpack the structure and pass each member. It seems better to
pass the whole structure instead, as with the C library. Also add an rtc_
prefix.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/rtc/bfin_rtc.c b/drivers/rtc/bfin_rtc.c
index 6cb1eba..a079a1d 100644
--- a/drivers/rtc/bfin_rtc.c
+++ b/drivers/rtc/bfin_rtc.c
@@ -67,8 +67,7 @@
 	wait_for_complete();
 
 	/* Calculate number of seconds this incoming time represents */
-	remain = mktime(tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
-			tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
+	remain = rtc_mktime(tmp);
 
 	/* Figure out how many days since epoch */
 	days = remain / NUM_SECS_IN_DAY;