Adding support for Analog Devices MAX313XX series RTCs.
This is ported from the Linux driver and adapted for use in u-boot.
Notable differences are
- handling of tm_year and tm_mon differ
- clock source support is omitted
- hwmon support for the MAX31328 and MAX31343 is omitted
- rtc_ops->reset is added
Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
