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>
3 files changed