dt-bindings: iio: pressure: Support Honeywell mprls0025pa sensor

Honeywell mprls0025pa is a pressure sensor series. There are many
different models with different pressure ranges, units and transfer
functions.

The range and transfer function need to be set up in the dt. Therefore
new properties honeywell,pmin-pascal, honeywell,pmax-pascal,
honeywell,transfer-function are introduced.

Add dt-bindings.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Andreas Klinger <ak@it-klinger.de>
Link: https://lore.kernel.org/r/ZGNpve4ux5KJ3BNQ@arbad


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