libmgcp: add enum mgcp_role

This enum indicates if the mgcp is running on the BSC or the BSC-NAT.
diff --git a/openbsc/src/libmgcp/mgcp_vty.c b/openbsc/src/libmgcp/mgcp_vty.c
index 69984ee..833908a 100644
--- a/openbsc/src/libmgcp/mgcp_vty.c
+++ b/openbsc/src/libmgcp/mgcp_vty.c
@@ -898,7 +898,8 @@
 	return 0;
 }
 
-int mgcp_parse_config(const char *config_file, struct mgcp_config *cfg)
+int mgcp_parse_config(const char *config_file, struct mgcp_config *cfg,
+		      enum mgcp_role role)
 {
 	int rc;
 	struct mgcp_trunk_config *trunk;
@@ -935,6 +936,7 @@
 			return -1;
 		}
 	}
+	cfg->role = role;
 
 	return 0;
 }
diff --git a/openbsc/src/osmo-bsc_mgcp/mgcp_main.c b/openbsc/src/osmo-bsc_mgcp/mgcp_main.c
index 540f760..596ea8a 100644
--- a/openbsc/src/osmo-bsc_mgcp/mgcp_main.c
+++ b/openbsc/src/osmo-bsc_mgcp/mgcp_main.c
@@ -223,7 +223,7 @@
 
 	handle_options(argc, argv);
 
-        rc = mgcp_parse_config(config_file, cfg);
+	rc = mgcp_parse_config(config_file, cfg, MGCP_BSC);
 	if (rc < 0)
 		return rc;
 
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c b/openbsc/src/osmo-bsc_nat/bsc_nat.c
index 897c657..1eac983 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c
@@ -1515,7 +1515,7 @@
 
 	/* init vty and parse */
 	telnet_init(tall_bsc_ctx, NULL, 4244);
-	if (mgcp_parse_config(config_file, nat->mgcp_cfg) < 0) {
+	if (mgcp_parse_config(config_file, nat->mgcp_cfg, MGCP_BSC_NAT) < 0) {
 		fprintf(stderr, "Failed to parse the config file: '%s'\n", config_file);
 		return -3;
 	}