spi: mxs: Drop GPIO includes

This driver is not using any symbols from the GPIO .h files
so drop them.

It was however implicitly using <linux/pinctrl/consumer.h>
so include that instead.

Cc: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200317092457.264055-1-linus.walleij@linaro.org


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