spi: dt-bindings: Drop Pratyush Yadav

Emails to Pratyush Yadav bounce ("550 Invalid recipient"). Generic SPI
properties should be maintained by subsystem maintainer (Mark). Add
recent contributor Vaishnav Achath to the Cadence SPI bindings.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220811063826.7620-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

spi: dt-bindings: cdns,qspi-nor: Move peripheral-specific properties out

The spi-peripheral-props.yaml schema contains peripheral-specific
properties for SPI controllers that should be present in the peripheral
node. Move peripheral-specific properties to a separate file and refer
to it in spi-peripheral-props.yaml.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20211109181911.2251-3-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>