staging: iio: resolver: ad2s1210: remove call to spi_setup()

This removes the call to spi_setup() in the ad2s1210 driver.

Setting MODE_3 was incorrect. It should be MODE_1 but we can let the
device tree select this and avoid the need to call spi_setup().
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20230929-ad2s1210-mainline-v3-3-fa4364281745@baylibre.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/staging/iio/resolver/ad2s1210.c

@@ -683,8 +683,6 @@ static int ad2s1210_probe(struct spi_device *spi)
 		return ret;
 
 	st->fclkin = spi->max_speed_hz;
-	spi->mode = SPI_MODE_3;
-	spi_setup(spi);
 	ad2s1210_initial(st);
 
 	return 0;