input_gpio: Fix not using latest pin state on pm resume

When the device was suspended and the pin level changed during
that time, the pin level of course isn't updated in the pins cb_data.
Once the device is resumed, this leads to potentially having
a wrong value in the pin state data leading to swallowing the first
event due to comparing the stored level vs. the new level before
reporting.

Also added some `const`s and deleted an unused struct element.

Signed-off-by: Marcel Krüger <marcel@mkgr.dev>

drivers/input/input_gpio_keys.c

@@ -33,7 +33,6 @@ struct gpio_keys_pin_data {
 	const struct device *dev;
 	struct gpio_keys_callback cb_data;
 	struct k_work_delayable work;
-	int8_t pin_state;
 };
 
 struct gpio_keys_config {
@@ -107,11 +106,12 @@ static __maybe_unused void gpio_keys_poll_pins(struct k_work *work)
 
 static __maybe_unused void gpio_keys_change_deferred(struct k_work *work)
 {
-	struct k_work_delayable *dwork = k_work_delayable_from_work(work);
-	struct gpio_keys_pin_data *pin_data = CONTAINER_OF(dwork, struct gpio_keys_pin_data, work);
+	const struct k_work_delayable *dwork = k_work_delayable_from_work(work);
+	const struct gpio_keys_pin_data *pin_data =
+		CONTAINER_OF(dwork, struct gpio_keys_pin_data, work);
 	const struct device *dev = pin_data->dev;
 	const struct gpio_keys_config *cfg = dev->config;
-	int key_index = pin_data - (struct gpio_keys_pin_data *)cfg->pin_data;
+	const int key_index = pin_data - (struct gpio_keys_pin_data *)cfg->pin_data;
 
 #ifdef CONFIG_PM_DEVICE
 	struct gpio_keys_data *data = dev->data;
@@ -267,6 +267,7 @@ static int gpio_keys_pm_action(const struct device *dev,
 				k_work_reschedule(&pin_data[0].work,
 						  K_MSEC(cfg->debounce_interval_ms));
 			} else {
+				pin_data[i].cb_data.pin_state = gpio_pin_get_dt(gpio);
 				ret = gpio_pin_interrupt_configure_dt(gpio, GPIO_INT_EDGE_BOTH);
 				if (ret < 0) {
 					LOG_ERR("interrupt configuration failed: %d", ret);