net-snmp: include ipv6 address & route mibs

net-snmp: include ipv6 address & route mibs

description: Since IPv6 is present in everyday use, we need to include
  information about IPv6 addresses & routes in SNMP

example:
  IP-MIB::ipAddressOrigin.ipv6

  IP-MIB::ipAddressOrigin[ipv6]["00:00:00:00:00:00:00:00:00:00:00:00:00:00:00:01"] = manual
  IP-MIB::ipAddressOrigin[ipv6]["fd:00:00:09:02:55:00:00:00:00:00:00:00:00:01:01"] = manual
  IP-MIB::ipAddressOrigin[ipv6]["fe:80:00:00:00:00:00:00:0c:00:09:ff:fe:06:01:01"] = linklayer
  IP-MIB::ipAddressOrigin[ipv6]["fe:80:00:00:00:00:00:00:0c:02:09:ff:fe:00:01:01"] = linklayer
  IP-MIB::ipAddressOrigin[ipv6]["fe:80:00:00:00:00:00:00:ae:84:c6:ff:fe:25:8c:ce"] = linklayer

tested:
  23.05-snapshot
  master snapshot
  with LibreNMS, OpenWRT device IPv6 Addresses & Routes are properly recognized

Signed-off-by: Peca Nesovanovic <peca.nesovanovic@sattrakt.com>