whpx: arm64: clamp down IPA size

Code taken from HVF and adapted for WHPX use. Note that WHPX doesn't
have a default vs maximum IPA distinction.

Signed-off-by: Mohamed Mediouni <mohamed@unpredictable.fr>

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
6 files changed