power: core: add set_voltage_limit API

Add the power_supply_set_voltage_limit API which
allows the POWER_SUPPLY_PROP_VOLTAGE_MAX property
to be configured for a given power supply.

CRs-Fixed: 637169
Change-Id: Ib525366ff742ad31d81ffee75920c19a6f9e8de8
Signed-off-by: David Keitel <dkeitel@codeaurora.org>