init: Fix charger mode

lpm.rc is only processed by init when the device boots into charger
mode. In charger mode, init does not trigger the 'early-boot' and 'boot'
actions at all. It runs the 'charger' action instead.

Before this patch even core services were not started in charger mode,
as class_start was part of the non-existing 'boot' action.

Change-Id: I2d1e794a5a288abca33a59a00ae49ef02d111950

Patchset: 1
http://review.cyanogenmod.org/#/c/65053/