of_batterydata: add of_batterydata_get_best_profile API

This function simply queries POWER_SUPPLY_PROP_RESISTANCE_ID
from via the power supply framework for a given power supply.

It will find the closest matching profile contained within
batterydata_container_node which is matched via the
qcom,batt-id-kohm property.

Change-Id: I15a34b784cc23809df4db2deb583bd6c40bd182b
Signed-off-by: David Keitel <dkeitel@codeaurora.org>