tests: Add sequencing test

Add a small test (to be expanded later) to check behaviour of MCTP
packet sequencing.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
diff --git a/Makefile b/Makefile
index 6a7c46b..1084eec 100644
--- a/Makefile
+++ b/Makefile
@@ -18,7 +18,7 @@
 
 test_util_objs = tests/test-utils.o
 
-tests = test_eid
+tests = test_eid test_seq
 
 test_targets = $(tests:%=tests/%)