rtc: stop validating rtc_time after rtc_time_to_tm

rtc_time_to_tm never generates an invalid tm. It is not necessary to
validate it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
diff --git a/drivers/rtc/rtc-ab8500.c b/drivers/rtc/rtc-ab8500.c
index 24a0af6..98c7123 100644
--- a/drivers/rtc/rtc-ab8500.c
+++ b/drivers/rtc/rtc-ab8500.c
@@ -131,7 +131,7 @@
 	secs += get_elapsed_seconds(AB8500_RTC_EPOCH);
 
 	rtc_time_to_tm(secs, tm);
-	return rtc_valid_tm(tm);
+	return 0;
 }
 
 static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm)