avr_reset not resetting IO properly

[Nuxar1]

Calling avr_reset doesnt reset IO correctly. The next time the simulator is run, pullups won't be set correctly. The reason is that it thinks the values are already set in the function avr_raise_irq_float and simply returns.

To fix the issue a possible fix would be manually setting the value to 0 in avr_ioport_reset.