Merge branch 'mlxsw-router-fixes'

Merge branch 'mlxsw-router-fixes'

Jiri Pirko says:

====================
mlxsw: Router fixes

Ido says:

First two patches ensure we remove from the device's table neighbours
that are considered to be dead by the neighbour core.

The last patch removes nexthop groups from the device when they are no
longer valid.
====================

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