Add base support for GPIO presence

This is the starting code needed to build the application.

Change-Id: I46112a222afbc057ac4fc4f8fb2b4c83822023df
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/configure.ac b/configure.ac
index 1a2bb98..7abd732 100644
--- a/configure.ac
+++ b/configure.ac
@@ -53,5 +53,5 @@
 )
 
 # Create configured output
-AC_CONFIG_FILES([Makefile gpio-util/Makefile test/Makefile])
+AC_CONFIG_FILES([Makefile gpio-util/Makefile presence/Makefile test/Makefile])
 AC_OUTPUT