i386: use global kvm_state in hyperv_enabled() check

There is no need to use vCPU-specific kvm state in hyperv_enabled() check
and we need to do that when feature expansion happens early, before vCPU
specific KVM state is created.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20210422161130.652779-15-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>