Now that we have the ability to handle MSRs from user space and also to
select which ones we do want to prevent in-kernel KVM code from handling,
let's add a selftest to show case and verify the API.
Signed-off-by: Alexander Graf <graf@amazon.com>

Message-Id: <20200925143422.21718-9-graf@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>