FILO --> zelf format to reduce size to 32k below.

[YhLu]

Eric,

Can you add something in filo Makefile and make it produce zelf format?

If the size to be 32k below, for fallback boot the payload could be
FILO+Etherboot --> [384k, 416k](FILO) + [416k, 448k) (Etherboot) , instead
of putting the Etherboot in the [0,64k) of ROM, and FILO in the [384k,
448k).

Regards

YH