Add the definition for the new UEFI 2.6 EFI_HII_IMAGE_EX_PROTOCOL and EFI_IMAGE_DECODER_PROTOCOL. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Cecil Sheng <cecil.sheng@hpe.com> Reviewed-by: Samer El-Haj-Mahmoud <elhaj@hpe.com> Reviewed-by: Abner Chang <abner.chang@hpe.com> Reviewed-by: Eric Dong <eric.dong@intel.com>