The hidden processor flags HF_SMM_MASK and HF_SMM_INSIDE_NMI_MASK
are not needed if CONFIG_KVM_SMM is turned off.  Remove the
definitions altogether and the code that uses them.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>