DCMI: Read power value from the configured D-Bus object path

1) Parse the power_reading JSON configuration file to get
   the D-Bus object path for the power reading.
2) Read the power reading value from the specified D-Bus object.

Change-Id: I4b9f0703318e8db2c86d0b337e524eee6da33d08
Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
diff --git a/configure.ac b/configure.ac
index 0e124a3..ac42e1d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -152,6 +152,11 @@
       [CONTROL_HOST_OBJ_MGR="/xyz/openbmc_project/control"])
 AC_DEFINE_UNQUOTED([CONTROL_HOST_OBJ_MGR], ["$CONTROL_HOST_OBJ_MGR"], [The Control Host D-Bus Object Manager])
 
+# Power reading sensor configuration file
+AC_ARG_VAR(POWER_READING_SENSOR, [Power reading sensor configuration file])
+AS_IF([test "x$POWER_READING_SENSOR" == "x"],[POWER_READING_SENSOR="/usr/share/ipmi-providers/power_reading.json"])
+AC_DEFINE_UNQUOTED([POWER_READING_SENSOR], ["$POWER_READING_SENSOR"], [Power reading sensor configuration file])
+
 # Create configured output
 AC_CONFIG_FILES([Makefile test/Makefile softoff/Makefile softoff/test/Makefile])
 AC_OUTPUT