gpio: mpc8xxx: select GPIOLIB_IRQCHIP

This driver uses gpiochip_irq_reqres() and gpiochip_irq_relres() which
are only built with GPIOLIB_IRQCHIP=y. Add the missing Kconfig select.

Fixes: 7688a54 ("gpio: mpc8xxx: Make irq_chip immutable")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505180309.1nosQMkI-lkp@intel.com/
Acked-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20250519-gpio-irq-kconfig-fixes-v1-2-fe6ba1c6116d@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: Bartosz Golaszewski

drivers/gpio/Kconfig

@@ -479,7 +479,7 @@ config GPIO_MPC8XXX
 		   FSL_SOC_BOOKE || PPC_86xx || ARCH_LAYERSCAPE || ARM || \
 		   COMPILE_TEST
 	select GPIO_GENERIC
-	select IRQ_DOMAIN
+	select GPIOLIB_IRQCHIP
 	help
 	  Say Y here if you're going to use hardware that connects to the
 	  MPC512x/831x/834x/837x/8572/8610/QorIQ GPIOs.