SQL Server instances are always active-passive in a failover cluster: the instance is active on one node and passive on all other nodes. Different instances can be active on one of the nodes where other instances are passive, but this does not make the cluster active-active.
That said, every node in a cluster that does not have any active instance can be treated as a passive and does not need a license. In SQL Server 2014, this is a benefit of Software Assurance: if you don't have SA, you need to fully license your passive nodes. Since you're running SQL 2012, it's not your case.