net/mlx5e: Split the main flow steering table

Currently, the main flow table is used for two purposes:
One is to do mac filtering and the other is to classify
the packet l3-l4 header in order to steer the packet to
the right RSS TIR.

This design is very complex, for each configured mac address we
have to add eleven rules (rule for each traffic type), the same if the
device is put to promiscuous/allmulti mode.
This scheme isn't scalable for future features like aRFS.

In order to simplify it, the main flow table is split to two flow
tables:
1. l2 table - filter the packet dmac address, if there is a match
we forward to the ttc flow table.

2. TTC (Traffic Type Classifier) table - classify the traffic
type of the packet and steer the packet to the right TIR.

In this new design, when new mac address is added, the driver adds
only one flow rule instead of eleven.

Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>