tbf/test: Add tests for RACH while DL TBFs are active

This adds tests for
- RA update with RACH for the RAUpdateComplete message
- RACH for UL while DL is active (LLC queue not empty)

Sponsored-by: On-Waves ehf
diff --git a/tests/tbf/TbfTest.ok b/tests/tbf/TbfTest.ok
index 274f069..a29105e 100644
--- a/tests/tbf/TbfTest.ok
+++ b/tests/tbf/TbfTest.ok
@@ -12,3 +12,9 @@
 === end test_tbf_single_phase ===
 === start test_tbf_two_phase ===
 === end test_tbf_two_phase ===
+=== start test_tbf_ra_update_rach ===
+=== end test_tbf_ra_update_rach ===
+=== start test_tbf_dl_flow_and_rach_two_phase ===
+=== end test_tbf_dl_flow_and_rach_two_phase ===
+=== start test_tbf_dl_flow_and_rach_single_phase ===
+=== end test_tbf_dl_flow_and_rach_single_phase ===