dt-bindings: iio: afe: voltage-divider: Add io-channel-cells

Enable the voltage divider to both receive and provide measurement
services by adding #io-channel-cells.

This is especially valuable in scenarios where an ADC has an analog
frontend, like a voltage divider, and obtaining its raw value isn't
interesting. It is desired to get the real voltage before the voltage
divider.

Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240206105502.648255-1-naresh.solanki@9elements.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings: iio: afe: voltage-divider: Spelling s/curcuit/circuit/

Fix a misspelling of "circuit".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/a8597e54b55dedc51025fe3073d25ef0d659d0dc.1686045793.git.geert+renesas@glider.be
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings:iio:afe:voltage-divider: txt to yaml conversion

Simple binding so straight forward conversion, though did require
adding a separate binding document for the max1027 to reflect
its abilities to provide channels to consumers.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20201031181242.742301-9-jic23@kernel.org