power: smb5: Add support for PPS constant current(CC) mode

Add support for PPS CC mode charging for dual charge pumps
with MID-VBAT configuration.

If a charging adapter is put in constant current (CC) mode during charging,
the supply provides the requested constant current. As a result, its output
voltage is automatically adjusted according to the load, and falls into
charge pump operational range.

For CC mode add an ability to configure the ICL and main-charger's FCC
current using power-supply properties.

Use POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT to report the total
FCC which can be pumped into the battery at that point in time.

On charger removal, reset all the votes casted during CC mode.

Change-Id: I242e92b87753d962289c94eedb054b2e8b67b99d
Signed-off-by: Sahil Chandna <chandna@codeaurora.org>