Merge pull request #7485 from aabadie/stm32_cleanup_vectors

cpu/stm32f0/include/cpu_conf.h

cpu/stm32f0/vectors.c

cpu/stm32f1/include/cpu_conf.h

cpu/stm32f1/vectors.c

cpu/stm32f2/vectors.c

cpu/stm32f3/include/cpu_conf.h

cpu/stm32f3/vectors.c

cpu/stm32f4/include/cpu_conf.h

cpu/stm32f4/include/vendor/stm32f410rx.h

cpu/stm32f4/vectors.c

cpu/stm32l0/include/cpu_conf.h

cpu/stm32l0/vectors.c

cpu/stm32l1/include/cpu_conf.h

cpu/stm32l1/include/vendor/stm32l1xx.h

cpu/stm32l1/vectors.c

cpu/stm32l4/include/cpu_conf.h

cpu/stm32l4/vectors.c