Fuel-Gauge: Porting FuelGauge-driver changes to R3-ICS

Fuel-Gauge: Porting FuelGauge-driver changes to R3-ICS

BZ: 18239

This patch has the defect-fixes/enhancements from R2-stable to R3-ICS,
for FG-driver. This includes .c and .h files involved.
Signed-off-by: Pavan Kumar S <pavan.kumar.s@intel.com>
Change-Id: Ib74dd9447555df1ad858c541dd059ae01f510bbe
Reviewed-on: http://android.intel.com:8080/29732
Reviewed-by: Kumar S, Pavan <pavan.kumar.s@intel.com>
Reviewed-by: Souza, JasonX <jasonx.souza@intel.com>
Reviewed-by: Pallala, Ramakrishna <ramakrishna.pallala@intel.com>
Reviewed-by: Mukherjee, DevapriyaX <devapriyax.mukherjee@intel.com>
Reviewed-by: Gugwad, SantoshX <santoshx.gugwad@intel.com>
Tested-by: Gugwad, SantoshX <santoshx.gugwad@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>