sgsn/test: Add test case test_gmm_routing_areas

This test add different cases of routing area changes.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/tests/sgsn/sgsn_test.ok b/openbsc/tests/sgsn/sgsn_test.ok
index 7913a39..5b8fc40 100644
--- a/openbsc/tests/sgsn/sgsn_test.ok
+++ b/openbsc/tests/sgsn/sgsn_test.ok
@@ -25,6 +25,14 @@
   - sgsn_alloc_ptmsi
   - Repeated Attach Request
   - Repeated RA Update Request
+Testing routing area changes
+  - Attach Request (RA 1)
+  - RA Update Request (RA 1 -> RA 1)
+  - RA Update Request (RA 1 -> RA 2)
+  - Attach Request (RA 2)
+  - RA Update Request (RA other -> RA 2)
+  - Attach Request (RA 2)
+  - RA Update Request (RA 2 -> RA 2)
 Testing APN matching
 Testing GGSN selection
 Done