dt-bindings: iio: light: veml6075: document vishay,rset-ohms

The veml6070 provides a configurable integration time by means of an
external resistor (Rset in the datasheet) with values between 75 and
1200 kohms.

Document vishay,rset-ohms to select the integration time.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20241031-veml6070-integration-time-v4-1-c66da6788256@gmail.com


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