OM2000/RBS2000: Make IS+CON configuration persistent in config file

This uses the new bts_model->config_write_bts() callbacks
diff --git a/openbsc/src/bts_ericsson_rbs2000.c b/openbsc/src/bts_ericsson_rbs2000.c
index fa25f3a..ab29591 100644
--- a/openbsc/src/bts_ericsson_rbs2000.c
+++ b/openbsc/src/bts_ericsson_rbs2000.c
@@ -31,12 +31,6 @@
 
 #include "input/lapd.h"
 
-static struct gsm_bts_model model_rbs2k = {
-	.type = GSM_BTS_TYPE_RBS2000,
-	.name = "rbs2000",
-	.oml_rcvmsg = &abis_om2k_rcvmsg,
-};
-
 static void bootstrap_om_bts(struct gsm_bts *bts)
 {
 	LOGP(DNM, LOGL_NOTICE, "bootstrapping OML for BTS %u\n", bts->nr);
@@ -143,6 +137,18 @@
 	return 0;
 }
 
+static void config_write_bts(struct vty *vty, struct gsm_bts *bts)
+{
+	abis_om2k_config_write_bts(vty, bts);
+}
+
+static struct gsm_bts_model model_rbs2k = {
+	.type = GSM_BTS_TYPE_RBS2000,
+	.name = "rbs2000",
+	.oml_rcvmsg = &abis_om2k_rcvmsg,
+	.config_write_bts = &config_write_bts,
+};
+
 int bts_model_rbs2k_init(void)
 {
 	model_rbs2k.features.data = &model_rbs2k._features_data[0];