If MAC address read from nvmem efuse by calling .of_get_mac_address(),
but nvmem efuse is registerred later than the driver, then it
return -EPROBE_DEFER value. So modify the driver to support
defer probe when read MAC address from nvmem efuse.
Updates for v2:
avoid memory leak that the queues allocated by fec_enet_alloc_queue().
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>