Drop WARNINGS_ARE_ERRORS exceptions

Thanks to Bruce's great work, we can finally drop this workaround.

Change-Id: Ie92d1e53ef867fa34aa2489ccfb682d73195b213
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/3569
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>
7 files changed