arm/dt: msm8974: Reenable CC-based SoC and update r-sense

In order to get more data on the main BMS algorithm, reenable the CC
based SoC calculation.

In order to do this, the r-sense value must be updated to its current
real value. Currently, it is the old 10mOhm value from the pm8921-bms.
Change this to be 2mOhm, the standard value for the pm8941 external
r-sense.

Change-Id: I54220b006e8adcd4a3077a6fe06305633dcfb81b
Signed-off-by: Xiaozhe Shi <xiaozhes@codeaurora.org>