BSSMAP_Templates: Add missing tr_BSSMAP_HandoverPerformed template

The receive template for the BSSMAP HANDOVER PERFORMED MESSAGE is
missing, lets add one.

Related OS#3645

Change-Id: I527913203b2d5bfa26c181c4bb79481a9cd283ae
diff --git a/library/BSSMAP_Templates.ttcn b/library/BSSMAP_Templates.ttcn
index 118168e..d00a5ab 100644
--- a/library/BSSMAP_Templates.ttcn
+++ b/library/BSSMAP_Templates.ttcn
@@ -823,6 +823,26 @@
 	}
 }
 
+template PDU_BSSAP tr_BSSMAP_HandoverPerformed
+modifies tr_BSSAP_BSSMAP := {
+	pdu := {
+		bssmap := {
+			handoverPerformed := {
+				messageType := '17'O,
+				cause := ?,
+				cellIdentifier := ?,
+				chosenChannel := omit,
+				chosenEncryptionAlgorithm := omit,
+				lSAIdentifier := omit,
+				talkerPriority := omit,
+				codecList := omit,
+				speechCodec := omit,
+				lCLS_BSS_Status := omit
+			}
+		}
+	}
+}
+
 template BSSMAP_IE_IMSI ts_BSSMAP_Imsi(hexstring imsi_digits) := {
 	elementIdentifier := '08'O,
 	lengthIndicator := 0, /* overwritten */