cleanup of IOPort setup
cleanup of IOPort setup

joakimeriksson/mspsim,ransford/mspsim,mspsim/mspsim,nfi/mspsim,fvdnabee/mspsim,fvdnabee/mspsim,cmorty/mspsim,contiki-os/mspsim,cmorty/mspsim,ransford/mspsim,nfi/mspsim,mspsim/mspsim,joakimeriksson/mspsim,contiki-os/mspsim