T5506: Add link-local IPv6 address for container interfaces

Fix for adding IPv6 link-local address for container interfaces

set container network NET01 prefix '10.0.0.0/24'
set container network NET01 prefix '2001:db8:2222::/64'

% ip -6 addr show scope link dev pod-NET01
17: pod-NET01: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000

inet6 fe80::d89c:dfff:fe1a:8689/64 scope link