init: Bring back support for arbitrary chargermode cmdlines

This was accidentally removed while debugging the init breakage
fixed in change I8ef5c932efcd5e7f8d6f6fce0915683d84c3ee11. Put
it back

Change-Id: If35b9d5db281f8aab6de26f2bb63717d28b2db30
Merge remote-tracking branch 'cm/cm-12.0' into cm-12.0