fdc_isa_probe
static int fdc_isa_probe (device_t, cfdata_t, void *);
fdc_isa_probe, fdc_isa_attach, NULL, NULL);
static int fdc_isa_probe(device_t, cfdata_t, void *);
fdc_isa_probe, fdc_isa_attach, fdc_isa_detach, NULL, NULL, fdc_childdet);