Merge changes I1bfdc1f4,I09735f6e,I57f3333e,I37949113,Ic9e9ca4e into msm-3.0

* changes:
  power: pm8921-bms: add api to simultaneously read vbatt and ibatt
  power: pm8921-bms: calibrate xoadc more often
  power: pm8921-bms: add protection against divide by zero
  power: pm8921-charger: fix 10mv error on vdd_max
  power: pm8921-charger: fix reverse boosting