test: overlay: add missing include
Compiling the overlay unit test fails with odroid-c2_defconfig showing
errors like:
test/overlay/cmd_ut_overlay.c:29:8:
error: unknown type name ‘fdt32_t’
Add the missing include.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>