i386/kvm: hv-evmcs requires hv-vapic

Enlightened VMCS is enabled by writing to a field in VP assist page and
these require virtual APIC.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20190517141924.19024-9-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>