Custom U-Boot to detect OreSat Cards

[ryanpdx]

Need a custom u-boot image simular to BeagleBoards image that can detect our custom cards that will load our custom device trees.

U-boot will read the board ID from the Octavo A8's EEPROM to figure out which device tree to load.

Current we have a hack in place that symbolic links our custom device over the PocketBeagle's device tree during the images build process to get our custom device tree to load on boot.