rtc: cmos: remove stale REVISIT comments

It appears mc146818_get_time() and mc146818_set_time() now correctly
use the century register as specified in the ACPI FADT table. It is not
clear what else could be done here.

These comments were introduced by
        commit 7be2c7c9 ("[PATCH] RTC framework driver for CMOS RTCs")
in 2007, which originally referenced function get_rtc_time() in
include/asm-generic/rtc.h .
Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210716210437.29622-1-mat.jonczyk@o2.pl

drivers/rtc/rtc-cmos.c

@@ -229,19 +229,13 @@ static int cmos_read_time(struct device *dev, struct rtc_time *t)
 	if (!pm_trace_rtc_valid())
 		return -EIO;
 
-	/* REVISIT:  if the clock has a "century" register, use
-	 * that instead of the heuristic in mc146818_get_time().
-	 * That'll make Y3K compatility (year > 2070) easy!
-	 */
 	mc146818_get_time(t);
 	return 0;
 }
 
 static int cmos_set_time(struct device *dev, struct rtc_time *t)
 {
-	/* REVISIT:  set the "century" register if available
-	 *
-	 * NOTE: this ignores the issue whereby updating the seconds
+	/* NOTE: this ignores the issue whereby updating the seconds
 	 * takes effect exactly 500ms after we write the register.
 	 * (Also queueing and other delays before we get this far.)
 	 */