Avoid ISE use and switch to Vivado design

Introduce "fpga-image-adi-vivado" that builds the ADI reference design
for various boards, and also provides the export for u-boot-spl.

Rename fpga-image-adi to fpga-image-adi-ise for symmetry, and to
force reconsidering which version is to be used.

Upgrade kernel to match the new IP cores and configuration.