dt-bindings: iio: st-sensors: Fix repeated text

The description oddly contains a copy of the initial paragraph.
Let's not repeat ourselves.

Suggested-by: Diederik de Haas <didi.debian@cknow.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230329074614.1037625-1-linus.walleij@linaro.org


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