rtc: mpc5121: set range

The datasheet states that 4052 is the maximum value for year. However, the
mpc5121 read_time and set_time function abuse the target time register
instead of using the broken down time so it is limited to 2106.

Link: https://lore.kernel.org/r/20200306074404.58909-3-alexandre.belloni@bootlin.com


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