Although there's no reason we COULDN'T use tristate types, we haven't
up to this point. If there's a good reason to use them in the future,
this check can be removed.
Change-Id: I5f1903341f522bc957e394bc0fd288ba1adab431
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/13460
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
08ee1cfafc