board: sam9x60ek: remove nand init from board file

Move this out of board file as this is done by the DM based NAND flash
driver. The EBI chip select configuration, iomux and timings are
handled by the driver

Signed-off-by: Balamanikandan Gunasundar <balamanikandan.gunasundar@microchip.com>
2 files changed