eQos: Implement the read_rom_hwaddr callback

Implement the read_rom_hwaddr callback to load MAC address from fuse
for imx8m platforms.

Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>