Makefile changes for generating inventory-sensor-gen.cpp

Provide capability for the recipe to pass the config yaml as a
configurable output. Fallback to inventory-sensor-example.yaml
in case no config yaml is passed.

Change-Id: I6a069b0925c3e4c4d56bd1c9767b8fadcdf433b4
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/configure.ac b/configure.ac
index 1134046..4f534df 100644
--- a/configure.ac
+++ b/configure.ac
@@ -77,6 +77,10 @@
 SENSORGEN="$PYTHON ${srcdir}/scripts/sensor_gen.py -i $SENSOR_YAML_GEN"
 AC_SUBST(SENSORGEN)
 
+AS_IF([test "x$INVSENSOR_YAML_GEN" == "x"], [INVSENSOR_YAML_GEN="inventory-sensor-example.yaml"])
+INVSENSORGEN="$PYTHON ${srcdir}/scripts/inventory-sensor.py -i $INVSENSOR_YAML_GEN"
+AC_SUBST(INVSENSORGEN)
+
 # Soft Power off related.
 AS_IF([test "x$enable_softoff" != "xno"],
     # Dbus service name