The spi-peripheral-props.yaml schema contains peripheral-specific
properties for SPI controllers that should be present in the peripheral
node. Add a reference to that so its constraints are followed.

additionalProperties: false cannot be used since it marks the controller
properties as unknown. Use unevaluatedProperties: false instead. This
has the side effect of allowing extra properties that are not specified
in the schema. The alternative is to list all the controller properties
in this schema but that would mean every peripheral binding would have
to repeat the same set of properties for each controller.
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211109181911.2251-4-p.yadav@ti.comSigned-off-by: Mark Brown <broonie@kernel.org>