Input: add DA9062 OnKey capability to DA9063 OnKey driver

Add DA9062 OnKey support into the existing DA9063 OnKey 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 OnKey.

The following alterations have been made to the DA9063 OnKey:

- Addition of a da906x_chip_config structure to hold all
  generic registers and bitmasks for this type of OnKey component.
- Addition of an struct of_device_id table for DA9063 and DA9062
  defaults
- Refactoring functions to use struct da9063_onkey accesses to generic
  registers/masks instead of using defines from registers.h
- Re-work of da9063_onkey_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: Dmitry Torokhov <dmitry.torokhov@gmail.com>