i386: stop using env->features[] for filling Hyper-V CPUIDs

As a preparatory patch to dropping Hyper-V CPUID leaves from
feature_word_info[] stop using env->features[] as a temporary
storage of Hyper-V CPUIDs, just build Hyper-V CPUID leaves directly
from kvm_hyperv_properties[] data.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20210422161130.652779-5-vkuznets@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>