power: qpnp-bms: keep the IADC calibrated

With the current hardware, the IADC needs to be calibrated very often
because of temperature drifts. The BMS driver needs the IADC to be
calibrated all the time in order to keep the coulomb counter
accurate.

In every SoC recalculation, recalibrate the IADC. Also, setup BTM to
monitor the pmic die temperature. Wake the device up and recalibrate
if the temperature has drifted.

CRs-Fixed: 433840
CRs-Fixed: 477720
CRs-Fixed: 477717
Change-Id: I0193f9efdc23fbfe5ac93d061efe6e89d8a1bb6d
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>