staging: iio: ad2s1210: Remove platform data NULL check in probe

The driver only needs to access GPIOs via GPIOLIB. And SPI can be
configured via device-tree or ACPI.

The platform data is a remnant from another time, and should not cause the
driver to error out during probing if it is NULL.
Also, it's not used.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/resolver/ad2s1210.c

@@ -647,9 +647,6 @@ static int ad2s1210_probe(struct spi_device *spi)
 	struct ad2s1210_state *st;
 	int ret;
 
-	if (!spi->dev.platform_data)
-		return -EINVAL;
-
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)
 		return -ENOMEM;