spi: dt-bindings: samsung: Convert to dtschema

Convert the Samsung SoC (S3C24xx, S3C64xx, S5Pv210, Exynos) SPI
controller bindings to DT schema format.

The conversion also drops requirement from providing controller-data and
its data for each of SPI peripheral device nodes.  The dtschema cannot
express this and the requirement is being relaxed in the driver now.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220124082347.32747-2-krzysztof.kozlowski@canonical.com