media: atmel: atmel-isc: create an adapt pipeline callback for product specific

Once the pipeline is set in the base code, create a callback that will adapt
the ISC pipeline to each product.
Create the adapt_pipeline callback that will be used in this fashion.

[hverkuil: made isc_sama5d2_adapt_pipeline static]

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>