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: I0f975fb9d5da2368a915ba969ebffe96010d4fe8
Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
diff --git a/configure.ac b/configure.ac
index 66d4cb6..246d88f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -47,6 +47,9 @@
 AS_IF([test "x$FRU_YAML" == "x"], [FRU_YAML="writefru.yaml"])
 FRUGEN="$PYTHON $srcdir/writefru.py -i $FRU_YAML"
 AC_SUBST(FRUGEN)
+AS_IF([test "x$PROP_YAML" == "x"], [PROP_YAML="extra-properties-example.yaml"])
+PROPGEN="$PYTHON $srcdir/extra-properties.py -e $PROP_YAML"
+AC_SUBST(PROPGEN)
 
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([Makefile test/Makefile])