Added regression_test_vhdl key, and some tb.

libraries/io/eth/hdllib.cfg

libraries/io/eth/tb/vhdl/tb_tb_eth.vhd

libraries/io/i2c/hdllib.cfg

libraries/io/i2c/tb/vhdl/tb_tb_i2c_commander.vhd

libraries/io/mdio/hdllib.cfg

libraries/io/mdio/tb/vhdl/tb_mdio.vhd

libraries/io/mdio/tb/vhdl/tb_mdio_phy.vhd

libraries/io/mdio/tb/vhdl/tb_mdio_phy_ctlr.vhd

libraries/io/mdio/tb/vhdl/tb_mdio_phy_reg.vhd

libraries/io/tr_10GbE/hdllib.cfg

libraries/io/tr_10GbE/tb/vhdl/tb_tb_tr_10GbE.vhd