gpio/qoriq: select IRQ_DOMAIN

The gpio-mpc8xxx driver requires IRQ domains but can be built
without them, resulting on a failure to build certain randconfigs
on ARM:

drivers/gpio/gpio-mpc8xxx.c: In function 'mpc8xxx_gpio_to_irq':
drivers/gpio/gpio-mpc8xxx.c:92:10: error: implicit declaration of function 'irq_create_mapping' [-Werror=implicit-function-declaration]
return irq_create_mapping(mpc8xxx_gc->irq, offset);

This selects IRQ_DOMAIN from the driver to ensure we can build it.

Signed-off-by: Arnd Bergmann <[e-mail]>
Fixes: 5df7fd46b70b ("gpio/qoriq: Add qoriq platforms support")
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/Kconfig

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