build: Generate package-config file

Change-Id: Ib776dad5936f1542fd2855a67954f2959c23ef45
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/configure.ac b/configure.ac
index 770637c..b4bcc07 100644
--- a/configure.ac
+++ b/configure.ac
@@ -41,4 +41,5 @@
 AC_CONFIG_FILES([Makefile.interfaces],
     [${srcdir}/generate_makefile.sh ${srcdir} > Makefile.interfaces])
 AC_CONFIG_FILES([Makefile])
+AC_CONFIG_FILES([phosphor-dbus-interfaces.pc])
 AC_OUTPUT