This patch adds JPEG decoding support for CODA960, handling the JPEG
hardware directly. A separate JPEG decoder video device is created due
to the separate hardware unit and different supported pixel formats.
While the hardware can not change subsampling on the fly, it can decode
4:2:2 subsampled JPEG images into YUV422P.

[m.felsch@pengutronix.de: fix qsequence counting by explicitly
 checking for the !use_bit case]
[hverkuil-cisco@xs4all.nl: fix 'warning: missing braces around initializer']
[mchehab+huawei@kernel.org: fix 'BRACES: Unbalanced braces around else statement']
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>