gpiolib: cdev: remove redundant store of debounce_period_us

gpiolib: cdev: remove redundant store of debounce_period_us

debounce_setup() stores the debounce_period_us if the driver supports
debounce, but the debounce_period_us is also stored where debounce_setup()
is called, independent of whether the debounce is being perfomed by
hardware or software.

Remove the redundant storing of the debounce_period_us in
debounce_setup().

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241020115238.170994-1-warthog618@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>