Merge branch 'mlxsw-Add-neighbour-offload-indication'

Ido Schimmel says:

====================
mlxsw: Add neighbour offload indication

Neighbour entries are programmed to the device's table so that the
correct destination MAC will be specified in a packet after it was
routed.

Despite being programmed to the device and unlike routes and FDB
entries, neighbour entries are currently not marked as offloaded. This
patchset changes that.

Patch #1 is a preparatory patch to make sure we only mark a neighbour as
offloaded in case it was successfully programmed to the device.

Patch #2 sets the offload indication on neighbours.

Patch #3 adds a test to verify above mentioned functionality.

Patched iproute2 version that prints the offload indication is available
here [1].

[1] https://github.com/idosch/iproute2/tree/idosch-next
====================

Signed-off-by: David S. Miller <davem@davemloft.net>