cve-extra-exclusions: add db CVEs to exclusion list

Since Oracle relicensed bdb, the open source community is slowly but surely replacing bdb with
supported and open source friendly alternatives. As a result these CVEs are unlikely to ever be fixed.

Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>