Add decode params control and the associated structure to group
all the information that are needed to decode a reference frame as
is described in ITU-T Rec. H.265 section "8.3.2 Decoding process
for reference picture set".

Adapt Cedrus driver to these changes.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>