dt-bindings: remoteproc: mediatek: Support MT8188 dual-core SCP

Under different applications, the MT8188 SCP can be used as single-core
or dual-core.

Signed-off-by: Olivia Wen <olivia.wen@mediatek.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

Link: https://lore.kernel.org/r/20240430011534.9587-2-olivia.wen@mediatek.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>