net/mlx5: E-Switch, Provide flow dest when creating vport rx rule

Currently the destination for the representor e-switch rx rule is
a TIR number. Towards changing that to potentially be a flow table,
as part of enabling RSS for representors, modify the signature of
the related e-switch API to get a flow destination.

Signed-off-by: Gavi Teitz <gavi@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>