rtc: isl12022: specify range_min and range_max

The isl12022 can (only) keep track of times in the range
2000-2099. The data sheet says

  The calendar registers track date, month, year, and day of the week
  and are accurate through 2099, with automatic leap year correction.

The lower bound of 2000 is obtained by simply observing that its YR
register only counts from 00 through 99.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20220921114624.3250848-3-linux@rasmusvillemoes.dk


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>