KVM: arm64: Force HCR_E2H in guest context when ARM64_KVM_HVHE is set

Also make sure HCR_EL2.E2H is set when switching HCR_EL2 in guest
context.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230609162200.2024064-16-maz@kernel.org


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>