The static arrays notch and sine are read-only so it make sense
to make them const.
Signed-off-by: NColin Ian King <colin.i.king@gmail.com>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@kernel.org>