buildroot

vboot-utils: add hash

vboot-utils had a hash file, but is says "none" because it is a git
download.  Since our git downloads are not reproducible, we can actually
add a hash.

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>