rtc: r9701: remove leftover comment

Commit 22652ba7 ("rtc: stop validating rtc_time in .read_time") removed
the code but not the associated comment.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201015191135.471249-1-alexandre.belloni@bootlin.com

drivers/rtc/rtc-r9701.c

@@ -85,10 +85,6 @@ static int r9701_get_datetime(struct device *dev, struct rtc_time *dt)
 	dt->tm_mon = bcd2bin(buf[4]) - 1; /* RMONCNT */
 	dt->tm_year = bcd2bin(buf[5]) + 100; /* RYRCNT */
 
-	/* the rtc device may contain illegal values on power up
-	 * according to the data sheet. make sure they are valid.
-	 */
-
 	return 0;
 }