mtd: spi-nor: Add support for is25lp016d

The is25lp016d is found on the iwg23s from iWave, therefore
add driver support for it so that we can upstream board support.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>