Simple conversion.

Added the #io-channel-cells optional property to allow for consumer
bindings if appropriate on a given board.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Mårten Lindahl <martenli@axis.com>
Link: https://lore.kernel.org/r/20200809111753.156236-8-jic23@kernel.org