tests: Add test_astlpc

Exercise message passing and packetisation over a dummy LPC interface
injected via the ops struct. The main() plays the role of the host.

Test suite code coverage for libmctp as a whole is lifted from ~34%
(lines and functions) to ~53% (lines and functions).

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Change-Id: Ied17b7fcf9b996c08ea7bea554ef4112ef0005c0
diff --git a/Makefile.am b/Makefile.am
index f187d9c..e967280 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -34,7 +34,8 @@
 
 TESTS = $(check_PROGRAMS)
 
-check_PROGRAMS = tests/test_eid tests/test_seq tests/test_bridge
+check_PROGRAMS = tests/test_eid tests/test_seq tests/test_bridge \
+		 tests/test_astlpc
 # We set a global LDADD here, as there's no way to specify it for all
 # tests. This means other targets' LDADDs need to be overridden.
 LDADD = tests/libtest-utils.a libmctp.la