nVMX: Mark bit 39 of MSR_IA32_VMX_EPT_VPID_CAP as reserved

Remove bit 39, which is defined as reserved in Intel's SDM, from the set
of allowed-1 bits in MSR_IA32_VMX_EPT_VPID_CAP.

Fixes: 69c8d31c ("VMX: Validate capability MSRs")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200207174244.6590-4-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>