powerpc/powernv: Handle OPAL_WRONG_STATE in opal_get_sensor_data()

OPAL returns OPAL_WRONG_STATE upon failing to provide sensor data due to
core sleeping/offline. Add a check in opal_get_sensor_data() for sensor
read failure with OPAL_WRONG_STATE return code and return -EIO.
Signed-off-by: Vipin K Parashar <vipin@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/opal-sensor.c

@@ -64,6 +64,10 @@ int opal_get_sensor_data(u32 sensor_hndl, u32 *sensor_data)
 		*sensor_data = be32_to_cpu(data);
 		break;
 
+	case OPAL_WRONG_STATE:
+		ret = -EIO;
+		break;
+
 	default:
 		ret = opal_error_code(ret);
 		break;