[PATCH 5.10/5.15/6.1 0/1] staging: iio: resolver: ad2s1210: remove call to spi_setup()

[Aleksandr Mishin]

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().
This issue has been fixed by the following patch which can be
cleanly applied to the 5.10/5.15/6.1.y branches.