rtc: mv: add range

This RTC handles time from 2000-01-01 00:00:00 to 2099-12-31 23:59:59 with
a weird rollover to 2000-06-23 00:00:00.

Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>