power_supply: Enable battery-charger for 88pm860x

There are charger and battery measurement feature for 88pm860x PMIC.

For charger, it can support pre-charge with small current when battery is
nearly exausted and then changed into fast-charge with CC&CV mode.

For battery monitor, it can support battery measurement such as
vbat,vsys,vchg and ibat etc,it can aslo accumulating the Coulomb value
charged or discharged from battery based on Conlomb Counter, we use it
to estimate battery capacity.

Signed-off-by: Jett.Zhou <jtzhou@marvell.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>