[media] atmel-isc: add the Image Sensor Controller code

Add driver for the Image Sensor Controller. It manages
incoming data from a parallel based CMOS/CCD sensor.
It has an internal image processor, also integrates a
triple channel direct memory access controller master
interface.

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>