power: pm8921-bms: account for capacitive drop

As the battery discharges, we need to account for the voltage drop across
capacitance in the battery. This voltage drop can be simulated using
a resistance in series with the battery such that it increases as state of
charge of the battery decreases.

Add parameter to account for this resistance in the profile tables.

Change-Id: Ic67b798ae8f480d8f42d9321e3847c4294bf7db3
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>