bump SPI clock to /2 because assembly expects that speed
bump SPI clock to /2 because assembly expects that speed

Arduboy/Arduboy,yyyc514/ArduboyLib,chcbaram/Arduboy,yyyc514/ArduboyLib,Arduboy/Arduboy,davidperrenoud/Arduboy,chcbaram/Arduboy,davidperrenoud/Arduboy