We want these to be zero or one, but by mistake we also accept negative
values.  It's harmless but we should still clean it up.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>