As the SAMA5D2 controller supports the 32-bit ECC strength, accept it
as a valid setting when required by the device tree or the NAND
parameter page.

Then configure the controller to use this new setting.

For the binding:
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NRomain Izard <romain.izard.pro@gmail.com>
Tested-by: NWenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>