Add missing EFIAPI modifiers to the functions that are exposed via the PCI I/O protocol. At the same time, add a missing UINT8 cast which breaks the build on Visual Studio. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Dandan Bi <dandan.bi@intel.com>