power: qpnp-bms: Improve logic for storing FCC learnt data

BMS module supports 16 (8-bit) battery backed-up registers.
Make sure that while backing-up the new data, always replace
the oldest stored data.

CRs-Fixed: 730047
Change-Id: I5fc406ec24ce242b722926cc1096f7dcaf561656
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>
Merge "power: qpnp-bms: Improve logic for storing FCC learnt data"
Merge "Merge "power: qpnp-bms: Improve logic for storing FCC learnt data""
Merge fb7dd7112d4b6429d86303f302738b6a640023c7 on remote branch

Change-Id: I505fd371843b15e15e4c8a29ef2c4c039467dd48
Merge "Merge fb7dd7112d4b6429d86303f302738b6a640023c7 on remote branch"