scripts: Define CONFIG_XPL_BUILD for all xPL builds

The new name 'xPL' is intended to indicate a build of any phase which is
not U-Boot proper. Define it for all such phases.

Note that we also define CONFIG_SPL_BUILD for all xPL builds. This
preserves existing behaviour, but future patches will adjust that.

Signed-off-by: Simon Glass <sjg@chromium.org>
2 files changed