dt-bindings: iio: pressure: meas,ms5611: add max SPI frequency to the example

Added max SPI frequency setting to the example.

Signed-off-by: Mitja Spes <mitja@lxnav.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221021135827.1444793-4-mitja@lxnav.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>