net/mlx5e: Remove leftover declaration

This function was removed in the cited commit below.

Fixes: 13e509a4 ("net/mlx5e: Remove leftover code from the PF netdev being uplink rep")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>