gpio: select IRQ_DOMAIN for gpiolib irqchip helpers

These helpers depend on the IRQ_DOMAIN so select it explicitly,
as it will not be present on all platforms such as Intel
desktops and laptops using Intel-MID.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -56,6 +56,7 @@ config GPIO_ACPI
 	depends on ACPI
 
 config GPIOLIB_IRQCHIP
+	select IRQ_DOMAIN
 	bool
 
 config DEBUG_GPIO
@@ -710,7 +711,7 @@ config GPIO_AMD8111
 config GPIO_INTEL_MID
 	bool "Intel Mid GPIO support"
 	depends on PCI && X86
-	select IRQ_DOMAIN
+	select GPIOLIB_IRQCHIP
 	help
 	  Say Y here to support Intel Mid GPIO.