power_supply: Add new power supply AUTHENTIC property

It is possible that users can use non-standard chargers or use invalid
batteries especially with mobile devices.

This patch adds a new power supply property called 'AUTHENTIC' to
indicate this to the user(user space).

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>