iio: light: vcnl4000: Fix integration interval for vcnl4040
According to the data sheet it's 0.12 lux/step, not 0.024 lux/step as with the vcnl4200. See p. 8 in https://www.vishay.com/docs/84307/designingvcnl4040.pdf Broken-by: 5a441aad Signed-off-by: Guido Günther <agx@sigxcpu.org>