Merge pull request #7051 from OTAkeys/pr/stm32f7discovery

boards/stm32f7discovery/Makefile

boards/stm32f7discovery/Makefile.dep

boards/stm32f7discovery/Makefile.features

boards/stm32f7discovery/Makefile.include

boards/stm32f7discovery/board.c

boards/stm32f7discovery/dist/openocd.cfg

boards/stm32f7discovery/include/board.h

boards/stm32f7discovery/include/gpio_params.h

boards/stm32f7discovery/include/periph_conf.h

cpu/stm32_common/periph/rtc.c

cpu/stm32f7/include/cpu_conf.h

cpu/stm32f7/include/vendor/stm32f769xx.h

cpu/stm32f7/ldscripts/stm32f769ni.ld

cpu/stm32f7/vectors.c