iio: dac: stm32: add support for stm32f4

This adds support for STM32F4 Digital-To-Analog converter.
Add compatible configuration data to handle hfsel (not present
in stm32f4).

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
1 file changed