dt-bindings: iio: adc: Add support for MT7986

Add compatible string and specific clock property for mt7986.
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Link: https://lore.kernel.org/r/20230421132047.42166-3-linux@fw-web.deSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/mediatek,mt2701-auxadc.yaml

@@ -26,6 +26,7 @@ properties:
           - mediatek,mt2712-auxadc
           - mediatek,mt6765-auxadc
           - mediatek,mt7622-auxadc
+          - mediatek,mt7986-auxadc
           - mediatek,mt8173-auxadc
       - items:
           - enum: