Updated libopencm3 to current master. Made all examples compile again.

Be specifically careful with the usb examples. There is likely some
breakage to be expected, not sure I updated all the drivers to the
correct types for the respective chips.

examples/stm32/f4/stm32f4-discovery/mandelbrot/mandel.c

@@ -26,7 +26,7 @@
 static void clock_setup(void)
 {
 	/* Enable high-speed clock at 120MHz */
-	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_120MHZ]);
+	rcc_clock_setup_hse_3v3(&rcc_hse_8mhz_3v3[RCC_CLOCK_3V3_120MHZ]);
 
 	/* Enable GPIOD clock for LED & USARTs. */
 	rcc_periph_clock_enable(RCC_GPIOD);