sdhci_generic_tune
int sdhci_generic_tune(device_t brdev, device_t reqdev, bool hs400);
DEVMETHOD(mmcbr_tune, sdhci_generic_tune),
error = sdhci_generic_tune(bus, child, hs400);
error = sdhci_generic_tune(bus, child, hs400);
DEVMETHOD(mmcbr_tune, sdhci_generic_tune),
DEVMETHOD(mmcbr_tune, sdhci_generic_tune),