Added two pieces of debug info for gas gauge.

1) 1Hz sampling of the voltage and current can be optionally enable via:

   /sys/class/i2c-dev/i2c-1/device/1-0055/debug_enable

   Report is shown periodically in the kernel log, and it is disabled by default.

2) Qpassed gas gauge value is now reported along with regular battery stat broadcast.
   This value reports the relative coulumb counter in and out of the battery.
   The value can be read at:

   /sys/class/power_supply/bq27520-0/charge_counter

Change-Id: I3db6deda7367f88d3081470cc1e914a32e64e7ec
2 files changed