net/mlx5e: Fix MLX5E_100BASE_T define

Bit 25 of eth_proto_capability in PTYS register is
1000Base-TT and not 100Base-T.

Fixes: f62b8bb8 ('net/mlx5: Extend mlx5_core to
support ConnectX-4 Ethernet functionality')
Signed-off-by: Rana Shahout <ranas@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>