stm32/boards/NUCLEO_F413ZH: Remove STARTUP_FILE, it's defined globally.
stm32/boards/NUCLEO_F413ZH: Remove STARTUP_FILE, it's defined globally.

The Makefile now defines this variable to the correct value (but it can
still be overridden by a board if necessary).

selste/micropython,bvernoux/micropython,adafruit/circuitpython,henriknelson/micropython,tobbad/micropython,trezor/micropython,tobbad/micropython,pozetroninc/micropython,kerneltask/micropython,adafruit/circuitpython,adafruit/circuitpython,trezor/micropython,pfalcon/micropython,kerneltask/micropython,adafruit/circuitpython,pozetroninc/micropython,kerneltask/micropython,pfalcon/micropython,bvernoux/micropython,henriknelson/micropython,henriknelson/micropython,adafruit/circuitpython,bvernoux/micropython,pramasoul/micropython,MrSurly/micropython,pfalcon/micropython,selste/micropython,pramasoul/micropython,trezor/micropython,kerneltask/micropython,MrSurly/micropython,pfalcon/micropython,selste/micropython,pramasoul/micropython,trezor/micropython,adafruit/circuitpython,bvernoux/micropython,pramasoul/micropython,tobbad/micropython,bvernoux/micropython,henriknelson/micropython,selste/micropython,selste/micropython,trezor/micropython,MrSurly/micropython,pozetroninc/micropython,pozetroninc/micropython,kerneltask/micropython,pramasoul/micropython,tobbad/micropython,tobbad/micropython,pozetroninc/micropython,henriknelson/micropython,pfalcon/micropython,MrSurly/micropython,MrSurly/micropython