CMake: Add -Wmissing-prototypes flag
CMake: Add -Wmissing-prototypes flag

lclc/mcu,dbitbox/mcu,jonasschnelli/mcu,jonasschnelli/mcu,dbitbox/mcu,dbitbox/mcu,dbitbox/mcu,lclc/mcu,lclc/mcu,lclc/mcu,jonasschnelli/mcu