V4L/DVB (9791): pxa-camera: pixel format negotiation

Use the new format-negotiation infrastructure, support all four YUV422
packed and the planar formats.

The new translation structure enables to build the format
list with buswidth, depth, host format and camera format
checked, so that it's not done anymore on try_fmt nor
set_fmt.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>