This currently isn't needed by anything in the edk2 tree but
it's useful for externally maintained platforms which have
to set this register e.g. to disable alignment aborts.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael Zimmermann <sigmaepsilon92@gmail.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>