power: fg-alg: Improve capcity learning accuracy

Currently batt_soc_msb and delta_cc_pct are used for initial and
delta cc_uah calculation which resulting in losing some mah
during the calcualtions. Instead use 32 bit batt_soc and delta
cc_soc in centi percentage to improve the accuracy.

CRs-Fixed: 2225348
Change-Id: Idd3fea47a5e15a5db5734a3959a82d4e92aafa24
Signed-off-by: Vamshi Krishna B V <vbv@codeaurora.org>