Add code for AmigaOne board
  (preliminary merge to U-Boot, still WIP)

* Patch by Jon Diekema, 12 Nov 2002:
  - Adding URL for IEEE OUI lookup
  - Making the autoboot #defines dependent on CONFIG_AUTOBOOT_KEYED
    being defined.
  - In the CONFIG_EXTRA_ENV_SETTINGS #define, the root-on-initrd and
    root-on-nfs macros are designed to switch how the default boot
    method gets defined.