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-mpc5121.c b/drivers/rtc/rtc-mpc5121.c
index 4ca4daa..dd03642 100644
--- a/drivers/rtc/rtc-mpc5121.c
+++ b/drivers/rtc/rtc-mpc5121.c
@@ -122,7 +122,7 @@ static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	 */
 	mpc5121_rtc_update_smh(regs, tm);
 
-	return rtc_valid_tm(tm);
+	return 0;
 }
 
 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)