Adding new files overwrote the header with the empty file (ie 0xff),
so carve out some space.
BUG=chromium:445938
BRANCH=none
TEST=none
Change-Id: I91c292df381c2bac41c6cb9dda74dae99defd81d
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/12789
Tested-by: build bot (Jenkins)