The MAX31331 was not correctly updating the seconds when
setting the time and would return the seconds previously set.

Like the MAX31343, a delay needs to be added after setting the
time. Wait one second after writing so that the date command shows the
correct time.

Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Bruce Adams <bruce.adams@alliedtelesis.co.nz>
Signed-off-by: Ben Hoelker <ben.hoelker@alliedtelesis.co.nz>

When setting the time on the MAX31343, the time is not updated
for one second, and reading the time in this interval will give
the old time. Wait one second after writing so that the date
command will show the correct time when setting the clock.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Cc: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Chris Packham <judge.packham@gmail.com>

An invalid calculation made setting years 2100-2199 impossible.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Cc: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Chris Packham <judge.packham@gmail.com>

In some designs the MAX313xx RTC may need calibration to cope with
oscillator inaccuracies. Provide read8/write8 ops so that the registers
can be accessed. Because the driver covers a range of MAX313xx variants
no attempt is made to ensure the register is valid.

Signed-off-by: Chris Packham <judge.packham@gmail.com>

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>