boards: adapt stm32f[2|4|7] boards clock config

boards/f4vi1/include/periph_conf.h

boards/msbiot/include/periph_conf.h

boards/nucleo-f401/include/periph_conf.h

boards/nucleo-f410/include/periph_conf.h

boards/nucleo-f411/include/periph_conf.h

boards/nucleo-f446/include/periph_conf.h

boards/nucleo144-f207/include/periph_conf.h

boards/nucleo144-f412/include/periph_conf.h

boards/nucleo144-f413/include/periph_conf.h

boards/nucleo144-f429/include/periph_conf.h

boards/nucleo144-f446/include/periph_conf.h

boards/nucleo144-f722/include/periph_conf.h

boards/nucleo144-f746/include/periph_conf.h

boards/nucleo144-f767/include/periph_conf.h

boards/stm32f4discovery/include/periph_conf.h

boards/stm32f7discovery/include/periph_conf.h