vbe: Provide VPL binman-symbols for the next phase
Add support for moving from TPL->VPL->SPL so that the VPL build can fit
properly into the boot flow.
Use #ifdefs to avoid creating unwanted symbols which Binman would then
try (and perhaps fail) to provide.
Add debugging to indicate the next phase.
Signed-off-by: Simon Glass <sjg@chromium.org>
authored by