endp: add typeset for e1-endpoints

Add an endpoint typeset for E1 support, also lets add dummy callbacks
for the cleanup and rtp dispatch functionality.

Related: OS#2547
Change-Id: I68b719a906e8f7251f0ca8c74ceec73bc40376f7
diff --git a/include/osmocom/mgcp/mgcp_endp.h b/include/osmocom/mgcp/mgcp_endp.h
index 8fb8d2c..0f9110c 100644
--- a/include/osmocom/mgcp/mgcp_endp.h
+++ b/include/osmocom/mgcp/mgcp_endp.h
@@ -60,6 +60,7 @@
 /*! MGCP endpoint typeset */
 struct mgcp_endpoint_typeset {
 	struct mgcp_endpoint_type rtp;
+	struct mgcp_endpoint_type e1;
 };
 
 /*! static MGCP endpoint typeset (pre-initalized, read-only) */