Epi-/Pycardium function to read battery discharge current
Add an epicardium function to read the battery discharge current (the currently available epic_read_battery_current
function only reads the charging current according to the PMIC datasheet).
+ fix incorrect AMUX channel in the epic_read_chargein_current
+ add a missing case (battery discharge current) to the AMUX read switch
+ documentation improvements
Edited by Woazboat