RSL_Emulation: Permit registration of explicit Channel Number

During assignment or hand-over, a given TTCN-3 component may be
interested in registering more than one channel number.  Add an explicit
procedure port with associated registration procedure, similar to what
we already do in GSUP, MNCC and others.

Change-Id: Iba37bf9541c779b79e179f995cdfa677633fadeb
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 29150ce..7e5b675 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1222,6 +1222,7 @@
 	connect(vc_conn:BSSMAPEM, vc_BSSMAP:PROC);
 	connect(vc_conn:MGCP_PROC, vc_MGCP:MGCP_PROC);
 	connect(vc_conn:RSL, bts[0].rsl.vc_RSL:CLIENT_PT);
+	connect(vc_conn:RSL_PROC, bts[0].rsl.vc_RSL:RSL_PROC);
 	connect(vc_conn:BSSAP, vc_BSSMAP:CLIENT);
 	connect(vc_conn:MGCP, vc_MGCP:MGCP_CLIENT);
 	vc_conn.start(derefers(fn)(id));