Add static virNetDevGetifaddrsAddress to attempt to get the interface
IP address. If getifaddrs is not supported, fall back to
virNetDevGetIPv4AddressIoctl to get the IP address.

This allows IPv6 addresses to be used for <listen type='network>
with device-backed networks.

https://bugzilla.redhat.com/show_bug.cgi?id=1192318Signed-off-by: NLuyao Huang <lhuang@redhat.com>
Signed-off-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>