misc: Fix compilation of the test cases.
diff --git a/openbsc/tests/channel/channel_test.c b/openbsc/tests/channel/channel_test.c
index 1b01878..36d0572 100644
--- a/openbsc/tests/channel/channel_test.c
+++ b/openbsc/tests/channel/channel_test.c
@@ -77,3 +77,5 @@
 void input_event() {}
 void sms_alloc() {}
 
+struct tlv_definition nm_att_tlvdef;
+