dt-bindings: mtd: spi-nand: Add spi-peripheral-props.yaml reference

SPI peripheral device bindings need to reference spi-peripheral-props.yaml
in order to use various SPI controller specific properties. Otherwise,
the unevaluatedProperties check will reject any controller specific
properties.
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20220525205909.2486153-1-robh@kernel.org

Documentation/devicetree/bindings/mtd/spi-nand.yaml

@@ -11,6 +11,7 @@ maintainers:
 
 allOf:
   - $ref: "nand-chip.yaml#"
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
 
 properties:
   compatible: