iio: hi8435: Use gpiod_set_value_cansleep()

Use gpiod_set_value_cansleep() instead of gpiod_set_value() to support
the case when reset pin is connected to a GPIO expander. See ZII VF610
SCU4 AIB for one such example.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-iio@vger.kernel.org
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>