AFIO_EXTICR[1 to 4] registers were not beeing set correctly. You have to
force a 0 on the bits that are 0 for the mutex to work.
Thanks Linus Casassa <linus@lin.cl> for the patch!
All #includes now explicitly use the "<libopencm3/stm32/rcc.h>" format.
If you want to get rid of the "libopencm3" prefix in your local project you
can add a respective -I entry in your Makefile (not recommended though).
All .ld files and .a libs are installed in $(TOOLCHAIN_DIR)/lib
directly (as before), but are now renamed to avoid potential
conflicts now or in the future. Examples:
libopencm3_lpc13xx.a
libopencm3_lpc13xx.ld
libopencm3_stm32.a
libopencm3_stm32.ld
