iio: ltr501: ltr559: fix initialization of LTR501_ALS_CONTR

iio: ltr501: ltr559: fix initialization of LTR501_ALS_CONTR

The ltr559 chip uses only the lowest bit of the ALS_CONTR register to
configure between active and stand-by mode. In the original driver
BIT(1) is used, which does a software reset instead.

This patch fixes the problem by using BIT(0) as als_mode_active for
the ltr559 chip.

Fixes: 8592a7eefa54 ("iio: ltr501: Add support for ltr559 chip")
Signed-off-by: Oliver Lang <Oliver.Lang@gossenmetrawatt.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Tested-by: Nikita Travkin <nikita@trvn.ru> # ltr559
Link: https://lore.kernel.org/r/20210610134619.2101372-3-mkl@pengutronix.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>