net, ixgbe: handle link local multicast addresses in SR-IOV mode

In SR-IOV mode the PF driver acts as the uplink port and is
used to send control packets e.g. lldpad, stp, etc.

   eth0.1     eth0.2     eth0
   VF         VF         PF
   |          |          |   <-- stand-in for uplink
   |          |          |
  --------------------------
  |  Embedded Switch       |
  --------------------------
              |
             MAC   <-- uplink

But the embedded switch is setup to forward multicast addresses
to all interfaces both VFs and PF and onto the physical link.
This results in reserved MAC addresses used by control protocols
to be forwarded over the switch onto the VF.

In the LLDP case the PF sends an LLDPDU and it is currently
being forwarded to all the VFs who then see the PF as a peer.
This is incorrect.

This patch adds the multicast addresses to the RAR table in the
hardware to prevent this behavior.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>