boardstatus: Do not error out on unknown CPU/northbridge

On bot, stderr is unmonitored, so it make no sense to stop with an error.
Instead use some sensible guesses.

Change-Id: I6292e9fbf446b751471b95f86e7515c6680bddf3
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/4748
Tested-by: build bot (Jenkins)
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
1 file changed