linux-phytec-ti

rtc: ds1307: remove member nvram_offset from struct ds1307

Remove member nvram_offset from struct ds1307 and use the value stored
in struct chip_desc directly.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>