Initial version of Support for Nokia *Site BTS

This includes the MetroSite, but also other Nokia BTS models.
diff --git a/openbsc/src/libbsc/bts_init.c b/openbsc/src/libbsc/bts_init.c
index 87bdde0..693eca8 100644
--- a/openbsc/src/libbsc/bts_init.c
+++ b/openbsc/src/libbsc/bts_init.c
@@ -24,6 +24,7 @@
 	bts_model_rbs2k_init();
 	bts_model_nanobts_init();
 	bts_model_hslfemto_init();
+	bts_model_nokia_site_init();
 	/* Your new BTS here. */
 	return 0;
 }