Add an initial VPL build for sandbox. This includes the flow:
TPL (with of-platdata) -> VPL -> SPL -> U-Boot
To run it:
./tpl/u-boot-tpl -D
The -D is needed to get the default device tree, which includes the serial
console info.
Add a Makefile check for OF_HOSTFILE which is the option that enables
devicetree control on sandbox.
Signed-off-by: Simon Glass <sjg@chromium.org>
9ae25b9ac9