net/mlx5e: Support offloading tc priorities and chains for eswitch flows

Currently we fail when user specify a non-zero chain, this patch adds the
support for it and tc priorities. To get to a new chain, use the tc
goto action.

Currently we support a fixed prio range 1-16, and chain range 0-3.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>