User can configure default miss rule in order to skip matching in the user
domain and forward the packet to the kernel steering domain.  When user
requests a default miss rule, we add steering rule to forward the traffic
to the next namespace.

Link: https://lore.kernel.org/r/20200504053012.270689-5-leon@kernel.orgSigned-off-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Zhang <markz@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>