net/mlx5e: TC, Move flow hashtable to be per rep

To allow shared tc block offload between two or more reps of the
same eswitch, move the tc flow hashtable to be per rep, instead
of per eswitch.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>