Dynamic IPv6 assignment for sub-port is not working

Dynamic IPv6 assignment for sub-port is not working

Issue:
========
Dynamic IPv6 assignment is not working as expected for sub-ports(VLANs).
It was working for only trunk port.

Solution:
=========
IPv6 Unsolicited Periodic message is sendt out every minute from ODL
controller (Leader/Master Node for Cluster Setup) to all IPv6 VMs OF ports.
This will not work for Sub-port.Since RA packet is not checking for VLAN IDs.
As part of this fix, sending both Solicited RA and Unsolicited RA packets
to remote ELAN Group to reach all the VMs in the ELAN group. This way we
can achieve optimal way to sending perodically URA to all the IPv6 service
enabled VMs.

ACL Service Changes:
--------------------
Added code changes for allow ICMPv6 Router Advertisement packets from ODL
controller for unsolicited RA packets in EGRESS_ACL_ANTI_SPOOFING_TABLE(table 240).

For Solicited RA packets are sending out from ODL controller to VM port
directly instead of re-submitting back to Egress pipeline.

This changes will address the both RA packets from external router as well
as internal neutron router (ODL Controller) for each VM matching with
lport_tag, ICMPv6_Type=134 and IPv6_Src=fe80::/10 to allow in table 240.

Issue: NETVIRT-1245

Change-Id: Ifb75fcadd971e406674b6108ab0a9b3dc0b1f698
Signed-off-by: Karthikeyan Krishnan <karthikeyangceb007@gmail.com>