net/mlx5e: Correct phys_port_name for PF port

Currently PF phys_port_name is named as pfNvf-1 as vport number for PF
vport is 65535.
Correct PF's phys_port name as agreed upon name as pfN.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Vu Pham <vuhuong@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>