Make examples compile with latest revision of libopencm3

The change in examples/stm32/f1/stm32-h103/traceswo/traceswo.c needs
review. I do not own that particular hardware, nor am I knowledgable
about the tracing functionality of that chip.
Example for the STM32F0DISCOVERY board

This is a simple example that blinks the blue LED on the
DISCOVERY board using the systick timer. It has been adapted from
a test case of the STM32F0 libopencm3 PLL initialization code.
It also enables the MCO output to be able to measure the system clock
frequency.