arm64: dts: mediatek: mt8192: fix vencoder clock name

arm64: dts: mediatek: mt8192: fix vencoder clock name

Clock name should be `venc_sel` as per binding.
Fix the warning message :
arch/arm64/boot/dts/mediatek/mt8192-asurada-hayato-r1.dtb: vcodec@17020000: clock-names:0: 'venc_sel' was expected
        from schema $id: http://devicetree.org/schemas/media/mediatek,vcodec-encoder.yaml#

Fixes: aa8f3711fc87 ("arm64: dts: mt8192: Add H264 venc device node")
Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20231228113245.174706-4-eugen.hristev@collabora.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>