rtc: ds1347: fix value written to century register

In `ds1347_set_time()`, the wrong value is being written to the
`DS1347_CENTURY_REG` register.  It needs to be converted to BCD.  Fix
it.

Fixes: 147dae76 ("rtc: ds1347: handle century register")
Cc: <stable@vger.kernel.org> # v5.5+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20221027163249.447416-1-abbotti@mev.co.ukSigned-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-ds1347.c

@@ -112,7 +112,7 @@ static int ds1347_set_time(struct device *dev, struct rtc_time *dt)
 		return err;
 
 	century = (dt->tm_year / 100) + 19;
-	err = regmap_write(map, DS1347_CENTURY_REG, century);
+	err = regmap_write(map, DS1347_CENTURY_REG, bin2bcd(century));
 	if (err)
 		return err;