arm/dt: msm-pm8941: enable bms-use-voltage-soc

Enable the optional property qcom,bms-use-voltage-soc to make BMS
use voltage based SoC by default.

Many test devices are currently untrimmed, and the BMS's r_sense is
not calibrated. Use voltage based soc to report a reasonable SoC
that avoids UVLO.

Change-Id: I4ffcb518310245549f16b1ab94fd6812796c9e7f
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>