KVM: arm64: Fix EL2 S1 XN handling for hVHE setups

KVM: arm64: Fix EL2 S1 XN handling for hVHE setups

The current XN implementation is tied to the EL2 translation regime,
and fall flat on its face with the EL2&0 one that is used for hVHE,
as the permission bit for privileged execution is a different one.

Fixes: 6537565fd9b7f ("KVM: arm64: Adjust EL2 stage-1 leaf AP bits when ARM64_KVM_HVHE is set")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Fuad Tabba <tabba@google.com>
Link: https://msgid.link/20251210173024.561160-2-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>