In the scope of VOL-1595, multicast GEM port definitions
shall be read from the technology profile. Both Multicast
and VOD downstream GEM port definitions shall be read from
"downstream_gem_port_attribute_list" tag.

A sample downstream_gem_port_attribute_list JSON can be found in
"Changes to be made in VOLTHA/Open OMCI Adapter" section of the
Multicast Design Document for SEBA
(https://docs.google.com/document/d/1FNwkcDeVB3C2SpTJP_QrYTlC6sYFo_xwQnxASMk9x2U)

Change-Id: I11fef951c25ca4a25fb01473c558eb2cf967be27
diff --git a/pkg/techprofile/tech_profile_if.go b/pkg/techprofile/tech_profile_if.go
index 797edc8..cadca87 100644
--- a/pkg/techprofile/tech_profile_if.go
+++ b/pkg/techprofile/tech_profile_if.go
@@ -33,6 +33,7 @@
 	GetTrafficScheduler(tpInstance *TechProfile, SchedCfg *tp_pb.SchedulerConfig,
 		ShapingCfg *tp_pb.TrafficShapingInfo) *tp_pb.TrafficScheduler
 	GetTrafficQueues(tp *TechProfile, Dir tp_pb.Direction) ([]*tp_pb.TrafficQueue, error)
+	GetMulticastTrafficQueues(tp *TechProfile) []*tp_pb.TrafficQueue
 	GetGemportIDForPbit(tp *TechProfile, Dir tp_pb.Direction, pbit uint32) uint32
 	FindAllTpInstances(techProfiletblID uint32, ponIntf uint32, onuID uint32) []TechProfile
 }