net: asix: init ASIX AX88772B MAC from EEPROM

The device comes up with a MAC address of all zeros. We need to read the
initial device MAC from EEPROM so it can be set properly later.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: David S. Miller <davem@davemloft.net>