audiomixer: Remove useless defines
audiomixer: Remove useless defines

Change-Id: I7cd08c0450353b1458fb6b9374036f1ef81e3865

shelsonjava/kms-core,shelsonjava/kms-core,ESTOS/kms-core,shelsonjava/kms-core,ESTOS/kms-core,ESTOS/kms-core,ESTOS/kms-core,TribeMedia/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,Kurento/kms-core,TribeMedia/kms-core,Kurento/kms-core,Kurento/kms-core,Kurento/kms-core,TribeMedia/kms-core