build: Add missing inclusion of phosphor-logging

Phosphor-logging is picked up by the configure_ac.
Include it in the Makefile such that it's available
as defined by the pkgconfig.

Change-Id: I67f19f653428f37956406b2ab393684f96968614
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/Makefile.am b/Makefile.am
index d107521..00947ff 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -16,12 +16,14 @@
 phosphor_certificate_manager_LDFLAGS = \
 	$(SDBUSPLUS_LIBS) \
 	$(PHOSPHOR_DBUS_INTERFACES_LIBS) \
+	$(PHOSPHOR_LOGGING_LIBS) \
 	-lstdc++fs \
 	-lssl \
 	-lcrypto
 
 phosphor_certificate_manager_CXXFLAGS = \
 	$(SYSTEMD_CFLAGS) \
-	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS)
+	$(PHOSPHOR_DBUS_INTERFACES_CFLAGS) \
+	$(PHOSPHOR_LOGGING_CFLAGS)
 
 SUBDIRS = . test