ASoC: max98520: Drop pointless includes

This driver is already using solely GPIO descriptors and
do not need to include the legacy headers <linux/gpio.h>
or <linux/of_gpio.h>. Drop them.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230825-descriptors-asoc-max-v1-6-b212292b2f08@linaro.org


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