data_validator_group: add a method to get the state of the sensor with the provided index

validation/data_validator_group.h

@@ -111,6 +111,13 @@ public:
 	 */
 	uint32_t		failover_state();
 
+	/**
+	 * Get the error state of the sensor with the specified index
+	 *
+	 * @return		bitmask with error states of the sensor
+	 */
+	uint32_t		get_sensor_state(unsigned index);
+
 	/**
 	 * Print the validator value
 	 *