build : provide extra properties yaml as config

Make it possible for the openpower-vpd-parser recipe to be able to
supply the extra properties YAML as configurable input.

Use extra-properties-example.yaml as input.

Change-Id: I3cfffa6bb9709b4dbf5c487ab198960cc52e3863
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
diff --git a/configure.ac b/configure.ac
index 8ff7c91..c1ef974 100644
--- a/configure.ac
+++ b/configure.ac
@@ -59,6 +59,9 @@
 AS_IF([test "x$YAML_GEN" == "x"], [YAML_GEN="example.yaml"])
 FRUGEN="$PYTHON $srcdir/scripts/fru_gen.py -i $YAML_GEN"
 AC_SUBST(FRUGEN)
+AS_IF([test "x$PROP_YAML" == "x"], [PROP_YAML="extra-properties-example.yaml"])
+PROPGEN="$PYTHON $srcdir/scripts/extra-properties.py -e $PROP_YAML"
+AC_SUBST(PROPGEN)
 
 # Create configured output
 AC_CONFIG_FILES([Makefile])