Sleeping is safe inside spi_transfer_one_message, and some
GPIO chips are running on slow busses (such as I2C GPIO
expanders) and need to sleep for setting values.
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>