dt-bindings: mtd: brcmnand: Prevent NAND chip unevaluated properties

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.

Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/linux-mtd/20230619092916.3028470-11-miquel.raynal@bootlin.com