spi: pl022: Drop custom per-chip cs_control

Drop the custom cs_control() assigned through platform data,
we have no in-tree users and the only out-of-tree use I have
ever seen of this facility is to pull GPIO lines, which is
something the driver can already do for us.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210330164907.2346010-1-linus.walleij@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>