ArmPkg/ArmMmuLib ARM: disregard high memory when setting permissions

ArmPkg/ArmMmuLib ARM: disregard high memory when setting permissions

Ignore calls to ArmSetMemoryAttributes () when the region described
is outside of the 32-bit addressable range. This memory is not
mapped in the first place, and the current code does not deal with
the high bits correctly, resulting in hangs.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>