irqtest.hal: remove unnecessary read_gpio/write_gpio functs
irqtest.hal: remove unnecessary read_gpio/write_gpio functs

see https://github.com/machinekit/mksocfpga/issues/70#issuecomment-241243951

strahlex/machinekit,strahlex/machinekit,strahlex/machinekit,mhaberler/machinekit,ArcEye/MK-Qt5,ArcEye/MK-Qt5,strahlex/machinekit,ArcEye/MK-Qt5,mhaberler/machinekit,strahlex/machinekit,mhaberler/machinekit,strahlex/machinekit,ArcEye/MK-Qt5,mhaberler/machinekit,strahlex/machinekit,ArcEye/MK-Qt5,ArcEye/MK-Qt5,ArcEye/MK-Qt5,mhaberler/machinekit,mhaberler/machinekit,mhaberler/machinekit,mhaberler/machinekit,ArcEye/MK-Qt5