ARM/spi: spear: Drop PL022 num_chipselect

ARM/spi: spear: Drop PL022 num_chipselect

A previous refactoring moved the chip select number handling
to the SPI core and we missed a leftover platform data user
in the ST spear platform. The spear is not using this
chipselect or PL022 for anything and should be using device
tree like the rest of the platform so just delete the
offending platform data.

Cc: Viresh Kumar <vireshk@kernel.org>
Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20210408075045.3435046-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>