V4L/DVB (7336): soc-camera: streamline hardware parameter negotiation

Improve hardware parameter negotiation between the camera host driver and
camera drivers. Parameters like horizontal and vertical synchronisation,
pixel clock polarity shall be set depending on capabilities of the
parties.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>