power: stc3117-battery: add battery cutoff voltage monitoring

Add support to register for ADC notification for battery voltage
monitoring, this is to enable reporting of '0' SOC when battery voltage
falls below threshold voltage.

CRs-Fixed: 984825
Change-Id: I9ad9c4a5bb0e4710956aa6b40a1d27b70d72362a
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>