drivers/sensor: lis2dw12: fix for wrong gpio_callback handling

It seems that gpio_pin_disable_callback() has never been working
for that sensor as it was expected. We used there argument 'dev'
as its own (lis2dw12) device pointer. While this argument is a
gpio_port device pointer not lis2dw12 sensor device pointer. So
cfg->int_gpio_pin always tries to disable callback for some random
pin read from accidental data sector.

Signed-off-by: Michał Oleszczyk <oleszczyk.m@gmail.com>