build: add correct libsystemd dependency

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia6bb8d347f76ec3a6e8f8babe7da3e63cab907c0
diff --git a/test/Makefile.am b/test/Makefile.am
index 8484d62..6d249e2 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -19,7 +19,8 @@
 	$(GTEST_CPPFLAGS) \
 	$(AM_CPPFLAGS) \
 	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS) \
-	$(SDBUSPLUS_CFLAGS)
+	$(SDBUSPLUS_CFLAGS) \
+	$(SYSTEMD_CFLAGS)
 
 test_cxxflags = \
 	$(PTHREAD_CFLAGS)
@@ -30,7 +31,8 @@
 	$(PTHREAD_LIBS) \
 	$(OESDK_TESTCASE_FLAGS) \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS) \
-	$(SDBUSPLUS_LIBS)
+	$(SDBUSPLUS_LIBS) \
+	$(SYSTEMD_LIBS)
 
 test_ldadd = \
 	$(top_builddir)/elog_serialize.o \