gpio: shared: extend the ifdef guard to gpio_shared_find_entry()

While this function is supposed to be used by all scanning functions, so
far we only have a single one for OF trees. Once we add support for ACPI
and software nodes, we'll drop the CONFIG_OF guard around this routine
but in order to avoid build warnings, let's extend it to cover it in the
meantime.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511180232.EItKeYjY-lkp@intel.com/
Link: https://lore.kernel.org/r/20251118-gpiolib-shared-of-guard-v1-1-e4ef149a2e0b@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpiolib-shared.c

@@ -58,6 +58,7 @@ static LIST_HEAD(gpio_shared_list);
 static DEFINE_MUTEX(gpio_shared_lock);
 static DEFINE_IDA(gpio_shared_ida);
 
+#if IS_ENABLED(CONFIG_OF)
 static struct gpio_shared_entry *
 gpio_shared_find_entry(struct fwnode_handle *controller_node,
 		       unsigned int offset)
@@ -72,7 +73,6 @@ gpio_shared_find_entry(struct fwnode_handle *controller_node,
 	return NULL;
 }
 
-#if IS_ENABLED(CONFIG_OF)
 static int gpio_shared_of_traverse(struct device_node *curr)
 {
 	struct gpio_shared_entry *entry;