Refer to Uefi spec 2.10 section 12.3.3, Add a new retval EFI_UNSUPPORTED to EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL.ReadKeyStrokeEx and EFI_SIMPLE_TEXT_INPUT_PROTOCOL.ReadKeyStroke(). Cc: Leif Lindholm <quic_llindhol@quicinc.com> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org> Cc: Abner Chang <abner.chang@amd.com> Cc: Liming Gao <gaoliming@byosoft.com.cn> Signed-off-by: Qingyu <qingyu.shang@intel.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>