hwmon: (max31827) Return closest value in update_interval

When user writes a value to update_interval which does not match the
possible values, instead of returning invalid error, return the closest
value.

Signed-off-by: Daniel Matyas <daniel.matyas@analog.com>
Link: https://lore.kernel.org/r/20231031182158.124608-4-daniel.matyas@analog.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>