[hybris-adaptors] add powerstate_path as parameter to start and stop the sensor
The startSensor and stopSensor methods in hybrisa-adaptors fail to start/stop the sensors on the devices thea and titan. They can be started/stoped using the enable file.
This change implements the powerstate_path as a parameter in the config file to start/stop the device using the same logic as in the sysfssensor based adaptors.