While using a different board, I realized that I did not configure the
ADC on all variants and there is a minor bug on the irq_num for
advanced 103 devices.
This modification adds support for a STM32ADC library. There are a
couple of examples on how to use it. The library allows usage of the
ADC with DMA in circular mode or scan mode, it allows the ADC to be
used in scan mode. And also to use the EOC interrupt.
More functionality needs to be added and will be in time.
Eventually the util files will be moved into the adc files in the core.