power: Add twl4030_madc battery driver.

This driver is used and tested on gta04 phone. It's using twl4030_madc
(similar to rx51 existing driver). Driver also implement charging and
discharging calibration data so user can define ranges and level.

Signed-off-by: Marek Belisko <marek@goldelico.com>
Signed-off-by: Lukas Märdian <lukas@goldelico.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>