ASoC: adau1701: Use gpio_set_value_cansleep()

The GPIO manipulation done by this driver is never in atomic context so
we can use gpio_set_value_cansleep() and support GPIOs that can't be set
from atomic context.

Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>