HiiImage.h uses EFI_GRAPHICS_OUTPUT_BLT_PIXEL which is defined in GraphicsOutput.h. Include GraphicsOutput.h to avoid build failure from consumer of HiiImage protocol. Contributed-under: TianoCore Contribution Agreement 1.0 Reviewed-by: Liming Gao <liming.gao@intel.com> Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>