net/mlx5: Introduce modify flow rule destination

This API is used for modifying the flow rule destination.
This is needed for modifying the pointed flow table by the
traffic type classifier rules to point on the aRFS tables.

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>