power: qpnp-qg: Add support for weighted capacity learning

Add support to loosen capacity learning qualifying criterion.
This helps to learn capacity from any starting battery SOC to
any ending battery SOC, provided, battery SOC changes by at least
10 % during charging. Assign weight to this capacity learning
event based on the change in battery SOC.

Change-Id: I110e0f032c1e402a624abe61e1d9ff06e6c73150
Signed-off-by: Umang Agrawal <uagrawal@codeaurora.org>