Remove deprecated assignments

tb/arp/test_arp.py

tb/arp_cache/test_arp_cache.py

tb/arp_eth_rx/test_arp_eth_rx.py

tb/arp_eth_tx/test_arp_eth_tx.py

tb/axis_baser_rx_64/test_axis_baser_rx_64.py

tb/axis_baser_tx_64/test_axis_baser_tx_64.py

tb/axis_gmii_rx/test_axis_gmii_rx.py

tb/axis_gmii_tx/test_axis_gmii_tx.py

tb/axis_xgmii_rx_32/test_axis_xgmii_rx_32.py

tb/axis_xgmii_rx_64/test_axis_xgmii_rx_64.py

tb/axis_xgmii_tx_32/test_axis_xgmii_tx_32.py

tb/axis_xgmii_tx_64/test_axis_xgmii_tx_64.py

tb/baser.py

tb/eth_axis_rx/test_eth_axis_rx.py

tb/eth_axis_tx/test_eth_axis_tx.py

tb/eth_mac_10g/test_eth_mac_10g.py

tb/eth_mac_10g_fifo/test_eth_mac_10g_fifo.py

tb/eth_mac_1g/test_eth_mac_1g.py

tb/eth_mac_1g_fifo/test_eth_mac_1g_fifo.py

tb/eth_mac_1g_gmii/test_eth_mac_1g_gmii.py