iio: dac: cio-dac: Fix typo in comment listing supported devices

This driver supports the CIO-DAC08 device and not "CIO-DAC06".

Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Link: https://lore.kernel.org/r/20230311002434.8761-1-william.gray@linaro.org


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>