gpiolib: remove unneeded #ifdef

We are already within another `#ifdef CONFIG_GPIOLIB_IRQCHIP` in
gpiochip_to_irq() so there's no need for another guard. Remove it.

Acked-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20250519-gpio-irq-kconfig-fixes-v1-3-fe6ba1c6116d@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: Bartosz Golaszewski

drivers/gpio/gpiolib.c

@@ -1888,15 +1888,13 @@ static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
 {
 	struct irq_domain *domain = gc->irq.domain;
 
-#ifdef CONFIG_GPIOLIB_IRQCHIP
 	/*
 	 * Avoid race condition with other code, which tries to lookup
 	 * an IRQ before the irqchip has been properly registered,
 	 * i.e. while gpiochip is still being brought up.
 	 */
 	if (!gc->irq.initialized)
 		return -EPROBE_DEFER;
-#endif
 
 	if (!gpiochip_irqchip_irq_valid(gc, offset))
 		return -ENXIO;