Revert "Revert "sec-battery: Standardize the output of the "online" property""

This reverts commit c71b8f76b6f1eee12167cdc59d052d47e9431f69.

Change-Id: I0f78dba48959345343dc3440f2c1fa1c5d0e42f7
sec-battery: let's override the charging mode only for LPM

There's no reason for this override in normal booting mode.

Change-Id: Ie370c17deddfee3372265cc1fa2bc1dc0e317269