Expand the SEV guest kbase guide with information about how to configure
a SEV/SEV-ES guest when attestation is required, and mention the use of
virt-qemu-sev-validate as a way to confirm it.
Reviewed-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>