Current max_register setting breaks reading nvram on certain chips and
also reading the standard registers on RX8130 where register map starts
at 0x10.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Fixes: 11e5890b "rtc: ds1307: convert driver to regmap"
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>