smb347_charger: power supply registration clean up

smb347_charger: power supply registration clean up

BZ: 31946

This patch  checks if the usb or mains charging is enabled by the
platform before registering with the power supply class. Also removes
few battery power supply attributes which are incorrectly implemented.

Change-Id: Ifb7c862bfcc2ccbdf149151a87bcccdbe2b45ef9
Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Reviewed-on: http://android.intel.com:8080/44466
Reviewed-by: Jena, TapanX <tapanx.jena@intel.com>
Reviewed-by: Tc, Jenny <jenny.tc@intel.com>
Tested-by: Kallappa Manjanna, MadhukumarX <madhukumarx.kallappa.manjanna@intel.com>
Reviewed-by: Koskinen, Ilkka <ilkka.koskinen@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>