found a small mistake in the f4 gpio initialization.

Author: tmb5932

src/core/io/platform/f4xx/GPIOf4xx.cpp

@@ -69,7 +69,6 @@ GPIOf4xx::GPIOf4xx(Pin pin, GPIO::Direction direction, Pull pull) : GPIO(pin, di
                   numOfPins,
                   static_cast<uint32_t>(direction),
                   static_cast<uint32_t>(pull),
-                  GPIO_PULLDOWN,
                   GPIO_SPEED_FREQ_HIGH);
 
     // TODO: double check that this actually applies to F4xx the same way it does to F3xx