dt-bindings: interrupt-controller: convert loongson,ls1x-intc.txt to json-schema

Convert the Loongson1 interrupt controller dt-bindings to json-schema.

Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230221102545.2103632-1-keguang.zhang@gmail.com


Signed-off-by: Rob Herring <robh@kernel.org>