Correct the phandle of power domain node referenced by vcodec nodes.

arch/arm64/boot/dts/mediatek/mt8173.dtsi:1450.35-1471.5: Warning (power_domains_property): /soc/vcodec@18002000: Missing property '#power-domain-cells' in node /soc/syscon@10006000 or bad phandle (referred from power-domains[0])
arch/arm64/boot/dts/mediatek/mt8173.dtsi:1502.35-1522.5: Warning (power_domains_property): /soc/vcodec@19002000: Missing property '#power-domain-cells' in node /soc/syscon@10006000 or bad phandle (referred from power-domains[0])

Fixes: d3dfd468 ("arm64: dts: mediatek: Update mt81xx scpsys node to align with dt-bindings")
Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
Link: https://lore.kernel.org/r/20220831065100.27722-1-tinghan.shen@mediatek.comSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>