cosmetic: move mgcp_release_endp() to mgcp_ep.c

- move mgcp_release_endp() to mgcp_ep.c since it is clearly
  an endpoint sicific function.

Change-Id: I0a65b6e906c52a9e7cd75c88c4cbe1bf473b866b
diff --git a/include/osmocom/mgcp/mgcp_ep.h b/include/osmocom/mgcp/mgcp_ep.h
index 74b3a9e..915f542 100644
--- a/include/osmocom/mgcp/mgcp_ep.h
+++ b/include/osmocom/mgcp/mgcp_ep.h
@@ -25,6 +25,7 @@
 
 struct sockaddr_in;
 struct mgcp_conn;
+struct mgcp_endpoint;
 
 /* Callback type for RTP dispatcher functions
    (e.g mgcp_dispatch_rtp_bridge_cb, see below) */
@@ -48,3 +49,5 @@
 
 /*! static MGCP endpoint typeset (pre-initalized, read-only) */
 extern const struct mgcp_endpoint_typeset ep_typeset;
+
+void mgcp_release_endp(struct mgcp_endpoint *endp);