This brings in the new ADC api for STM32 parts. Update to new standardized ADC apis. Drops pointless channel definitions, uses common names for common functions. No functional changes. Based on work in: https://github.com/libopencm3/libopencm3-examples/pull/130
Examples in these directories are not only for the board listed, they are simply preconfigured for those boards. If you do not find an example of the peripheral you want to use listed for your board, please look at the other boards. The differences between boards for the examples is normally only LEDs and buttons on different pins, and different memory sizes.