Use the new ArmLib helper to read the CPU's physical address limit so we can drop our own homecooked one. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>