qcom: battery: update FCC split policy

Use BATFET configuration exposed by parallel charger for
FCC split. In case of Stacked-BATFET main charger configured
to full FCC and parallel charger configured to 50% FCC and in
case of Non-Stacked-BATFET main charger configured to 50% FCC
and parallel charger configured to 50% FCC.

Change-Id: Ic75dd883a24fc4f87ecbd40c1d33249c18250fee
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>