Improve coreboot image detection heuristic

It's not absolutely perfect, but the likelihood of this check to fail is
0.000000000000000000000000013 (1.3*10^-26) which is good enough for me.

Corresponding to flashrom svn r292 and coreboot v2 svn r3408.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Stefan Reinauer <stepan@coresystems.de> 
1 file changed