intel_mid_power_off: modified charger detection

intel_mid_power_off: modified charger detection

BZ: 31318

Shutdown with SDP/CDP/DCP cable connected shall NOT RESET the system and enter
in Charging MODE
This shall be done ONLY with ACDC Charger
Signed-off-by: Gabriel Touzeau <gabrielx.touzeau@intel.com>
Change-Id: If6c8fc667930bd94f26493755eab36648182ec2e
Reviewed-on: http://android.intel.com:8080/46358
Reviewed-by: Pallala, Ramakrishna <ramakrishna.pallala@intel.com>
Tested-by: Romieu, Benoit <benoit.romieu@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>