[inga/regression-tests] Update ipv6 test to use new node_id-configured
EUI64-address scheme without MAC compatiblity and with local bit set.

Results in IPv6 addresses of form 'fe80::id'

For this, contiki-inga-main was modified to set U/L bit to 1
(in case of node_id of random generation) to indicate local EUI64 address.