Make sure the end of U-Boot is at 8-byte aligned offset, not 4-byte
aligned offset. This allows safely appending DT at the end of U-Boot
with the guarantee that the DT will be at 8-byte aligned offset. This
8-byte alignment is now checked by newer libfdt 1.7.2 .
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>