iio: light: veml6070: use unsigned int instead of unsigned

Trivial modification to use the recommended keyword 'int' after
'unsigned' for unsigned integers.

Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://patch.msgid.link/20241017-veml6070-integration-time-v1-1-3507d17d562a@gmail.com


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