compositemixer: Change to RAW caps
compositemixer: Change to RAW caps

Change-Id: I3dfce986241236b245434feb194076bee69f47a2

Kurento/kms-elements,TribeMedia/kms-elements,Kurento/kms-elements,shelsonjava/kms-elements,TribeMedia/kms-elements,shelsonjava/kms-elements,shelsonjava/kms-elements,Kurento/kms-elements,TribeMedia/kms-elements