misc: Firs round of fixing compilation of test cases

Next round should be using them again
diff --git a/openbsc/tests/channel/channel_test.c b/openbsc/tests/channel/channel_test.c
index ab165c7..4dcf69a 100644
--- a/openbsc/tests/channel/channel_test.c
+++ b/openbsc/tests/channel/channel_test.c
@@ -74,4 +74,5 @@
 
 void nm_state_event() {}
 void input_event() {}
+void sms_alloc() {}