iio: light: bh1750: Add hardware reset support via GPIO

iio: light: bh1750: Add hardware reset support via GPIO

Some BH1750 sensors require a hardware reset before they can be
detected on the I2C bus. This implementation adds support for an
optional reset GPIO that can be specified in the device tree.

The reset sequence pulls the GPIO low and then high before initializing
the sensor, which enables proper detection with tools like i2cdetect.
This is particularly important for sensors that power on in an
undefined state.

Signed-off-by: Sergio Perez <sergio@pereznus.es>
Link: https://patch.msgid.link/20250324135920.6802-2-sergio@pereznus.es
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>