neighbour: populate neigh_parms on alloc before calling ndo_neigh_setup

dev->ndo_neigh_setup() might need some of the values of neigh_parms, so
populate them before calling it.

Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>