The defines for the different build phases shouldn't be used in device
trees, currently they aren't even defined for device tree pre processing,
resulting in build errors.
Link: https://lists.denx.de/pipermail/u-boot/2025-March/582787.html
Signed-off-by: Hendrik Donner <hd@os-cillation.de>
Reviewed-by: Simon Glass <sjg@chromium.org>