Implements driver for the Vishay VEML6040 rgbw light sensor.

Included functionality: setting the integration time and reading the raw
values for the four channels

Not yet implemented: setting the measurements to 'Manual Force Mode' (Auto
measurements off, and adding a measurement trigger)

Datasheet: https://www.vishay.com/docs/84276/veml6040.pdfSigned-off-by: Arthur Becker <arthur.becker@sentec.com>
Link: https://lore.kernel.org/r/20240604-veml6040-v4-1-5a4d59597874@sentec.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>