Now that sandbox_vpl supports UPL, add a test that checks that the
payload can be loaded by SPL and the handoff information passed through
to U-Boot proper.
Signed-off-by: Simon Glass <sjg@chromium.org>
Use the sandbox_vpl build to test UPL since it supports a real devicetree
in SPL. The sandbox_spl build uses OF_PLATDATA.
Enable writing the UPL handoff in SPL and reading it in U-Boot proper.
Provide a test to check that this handoff works.
Note that the test uses the standard devicetree rather than the test one,
since it is a lot smaller and fits in the existing bloblist.
Signed-off-by: Simon Glass <sjg@chromium.org>