Ensure all raw NAND chip properties are valid by referencing the
relevant schema and set unevaluatedProperties to false in the NAND chip
section to avoid spurious additions of random properties.

Doing this in one location also saves us from dupplicating the
description of the NAND chip object.

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20230619092916.3028470-12-miquel.raynal@bootlin.com