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
README
This is a simple polling example that sends the value read out from the temperature sensor ADC channel of the STM32 to the USART2.
The terminal settings for the receiving device/PC are 115200 8n1.