dt-bindings: interrupt-controller: convert MediaTek sysirq to the json-schema

This helps validating DTS files.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240123060804.32254-1-zajec5@gmail.com


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