power: vm-bms: Disable charging on detecting a debug battery

Disable battery charging on detecting a debug board to avoid
damaging it.

Update read battery id function to read battery id_uv function
and add get_battery_id function to read the battery id.

Expose the battery-id via battery power supply class.

Change-Id: I644cb5b3e0daf019c9c7be297d6e86d9a109ac43
Signed-off-by: Kavya Nunna <knunna@codeaurora.org>