libosmo-mgcp-client: extend the mgcp_client for MGW pooling

At the moment the MGCP Client only supports one MGW per application.
Depending on the requirements of the application one MGW might not offer
the performance needed. Lets add support for an MGCP Client pool that is
backward compatible to existing applications.

Change-Id: Icaaba0e470e916eefddfee750b83f5f65291a6b0
Related: SYS#5091
diff --git a/src/libosmo-mgcp-client/mgcp_client_fsm.c b/src/libosmo-mgcp-client/mgcp_client_fsm.c
index 3f33dc7..1a2b6d8 100644
--- a/src/libosmo-mgcp-client/mgcp_client_fsm.c
+++ b/src/libosmo-mgcp-client/mgcp_client_fsm.c
@@ -252,6 +252,18 @@
 	return mgcp_ctx->conn_id;
 }
 
+/* Get the mgcp_client that is used with this mgcp_client_fsm instance */
+struct mgcp_client *mgcp_conn_get_client(struct osmo_fsm_inst *fi)
+{
+	struct mgcp_ctx *mgcp_ctx;
+
+	if (!fi)
+		return NULL;
+
+	mgcp_ctx = fi->priv;
+	return mgcp_ctx->mgcp;
+}
+
 static void mgw_crcx_resp_cb(struct mgcp_response *r, void *priv)
 {
 	struct osmo_fsm_inst *fi = priv;