arm/arm64: dts: mediatek: Add missing "#sound-dai-cells" to linux,bt-sco

Add missing "#sound-dai-cells" which is required by the linux,bt-sco
binding.

Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250409205001.1522009-1-robh@kernel.org


Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>