dt-bindings: iio: adc: adi,ad7606: add missing datasheet link

Add AD7606-5 datasheet link.
Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20240628-cleanup-ad7606-v2-1-96e02f90256d@baylibre.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml

@@ -11,6 +11,7 @@ maintainers:
 
 description: |
   Analog Devices AD7606 Simultaneous Sampling ADC
+  https://www.analog.com/media/en/technical-documentation/data-sheets/AD7605-4.pdf
   https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606_7606-6_7606-4.pdf
   https://www.analog.com/media/en/technical-documentation/data-sheets/AD7606B.pdf
   https://www.analog.com/media/en/technical-documentation/data-sheets/AD7616.pdf