iio: adc: add missing of_node references to iio_dev

Adding missing indio_dev->dev.of_node references to allow iio consumers
to access the device channels.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/adc/ad7476.c

@@ -227,6 +227,7 @@ static int ad7476_probe(struct spi_device *spi)
 
 	/* Establish that the iio_dev is a child of the spi device */
 	indio_dev->dev.parent = &spi->dev;
+	indio_dev->dev.of_node = spi->dev.of_node;
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = st->chip_info->channel;