Write everything needed for eMMC install into the gaps between
partitions on SD card. In that way, installation to eMMC only needs
the SD card, no additional files need to be loaded via TFTP any more.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Provide U-Boot variants for SD-card as well as eMMC boot, so we can
generate whole-disk images for the device.
While at it, rename 'mt7622' to 'mt7622-rfb1' to make it less confusing
now that more boards are being added.
Thanks to Frank Wunderlich (@frank-w) for making that nice SVG image
explaining the MMC boot process[1] and for providing the necessary
binary header blobs.
[1]: https://github.com/frank-w/BPI-R64-ATF
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
