arm64: dts: mediatek: add OPP support for mt8365 SoC

In order to have cpufreq support, this patch adds generic Operating
Performance Points support.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20230203-evk-board-support-v8-8-7019f3fd0adf@baylibre.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>