Dynamic EAPD nodes

In the current implementation EAPD nodes are fixed to a maximum of 5.

This is now changed to a dynamic OSArray, allowing the list of EAPD nodes to grow as more complex codecs are supported.

Additionally global variables are moved into the CodecCommander class as private members to prevent conflicts across multiple instances of CodecCommander attached to different audio codecs in a machine.

This is cumulative with the refactoring pull request.