dt-bindings: mtd: jedec, spi-nor: remove unneeded properties

After conversion the jedec,spi-nor DT schema to reference other schemas
(SPI and MTD) and use unevaluatedProperties, few properties are
redundant.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220408063720.12826-1-krzysztof.kozlowski@linaro.org