rtc: da9063: Add DA9062 RTC capability to DA9063 RTC driver

rtc: da9063: Add DA9062 RTC capability to DA9063 RTC driver

Add DA9062 RTC support into the existing DA9063 RTC driver component by
using generic access tables for common register and bit mask definitions.

The following change will add generic register and bit mask support to the
DA9063 RTC. The changes are slightly complicated by requiring support for
three register sets: DA9063-AD, DA9063-BB and DA9062-AA.

The following alterations have been made to the DA9063 RTC:

- Addition of a da9063_compatible_rtc_regmap structure to hold all generic
  registers and bitmasks for this type of RTC component.
- A re-write of struct da9063 to use pointers for regmap and compatible
  registers/masks definitions
- Addition of a of_device_id table for DA9063 and DA9062 defaults
- Refactoring functions to use struct da9063_compatible_rtc accesses to
  generic registers/masks instead of using defines from registers.h
- Re-work of da9063_rtc_probe() to use of_match_node() and dev_get_regmap()
  to provide initialisation of generic registers and masks and access to
  regmap

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>