External EEPROM / Internal OTP

At power-up, the LAN7850 searches for an external EEPROM. If an external EEPROM (93AA66A) is detected, the LAN7850 configuration is loaded from it. If no EEPROM is found, the device checks the OTP. If there is no OTP, the device uses default CSR settings. The EEPROM stores the default values for the USB descriptors and the MAC address.