In SR1.0, Internal TXC delay on transmit is always enabled. SR1.0 information is valid only for the AM571x family of devices.
In SR2.x, Internal TXC delay on transmit can be enabled or disabled
using bits [26] RGMII2_ID_MODE_N and [25] RGMII1_ID_MODE_N of the
CTRL_CORE_SMA_SW_1 register.