KVM: nSVM: Hide more stuff under CONFIG_KVM_HYPERV/CONFIG_HYPERV

'struct hv_vmcb_enlightenments' in VMCB only make sense when either
CONFIG_KVM_HYPERV or CONFIG_HYPERV is enabled.

No functional change intended.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Jeremi Piotrowski <jpiotrowski@linux.microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20231205103630.1391318-17-vkuznets@redhat.com


Signed-off-by: Sean Christopherson <seanjc@google.com>