[media] atmel-isc: add the isc pipeline function

Image Sensor Controller has an internal image processor.
It can convert raw format to the other formats, like
RGB565, YUV420P. A module parameter 'sensor_preferred'
is used to enable or disable the pipeline function.
Some v4l2 controls are added to tuning the image when
the pipeline function is enabled.

Signed-off-by: Songjun Wu <songjun.wu@microchip.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>