[beagleboard] beagle board USB-Boot

You have to have at-least something in either nand or on the sd card
to bring up the board with u-boot (and kernel, but you could tftp
that, and i'm not sure if the u-boot usb can read usb media yet)..
However beyond that, you can have everything else on the usb drive..


I guess you can boot -boot first from a SD card and then you can use a
USB stick to load kernel, fs or whatever