Add the Loongson platform spi binding with DT schema format using
json-schema.
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230613075834.5219-2-zhuyinbo@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>