qpnp-fg-gen3: prime CC_SOC_SW when capacity learning begins

CC_SOC_SW can accumulate error over time and get saturated high
during capacity learning. Prime it to a value based on battery
SOC when capacity learning begins. This way, it can be ensured
that CC_SOC_SW doesn't saturate in a capacity learning cycle.

Change-Id: I2866ed6dadee84e84bf28fb08dc3a5a0ae353852
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>