irqchip/meson: Add support for gpio interrupt controller

Add support for the interrupt gpio controller found on Amlogic's meson
SoC family.

This controller is a separate controller from the gpio controller. It is
able to spy on the SoC pad. It is essentially a 256 to 8 router with a
filtering block to select level or edge and polarity. The number of actual
mappable inputs depends on the SoC.

Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

drivers/irqchip/Kconfig

@@ -324,4 +324,12 @@ config IRQ_UNIPHIER_AIDET
 	help
 	  Support for the UniPhier AIDET (ARM Interrupt Detector).
 
+config MESON_IRQ_GPIO
+       bool "Meson GPIO Interrupt Multiplexer"
+       depends on ARCH_MESON || COMPILE_TEST
+       select IRQ_DOMAIN
+       select IRQ_DOMAIN_HIERARCHY
+       help
+         Support Meson SoC Family GPIO Interrupt Multiplexer
+
 endmenu

drivers/irqchip/Makefile

@@ -79,3 +79,4 @@ obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o irq-aspeed-i2c-ic.o
 obj-$(CONFIG_STM32_EXTI) 		+= irq-stm32-exti.o
 obj-$(CONFIG_QCOM_IRQ_COMBINER)		+= qcom-irq-combiner.o
 obj-$(CONFIG_IRQ_UNIPHIER_AIDET)	+= irq-uniphier-aidet.o
+obj-$(CONFIG_MESON_IRQ_GPIO)		+= irq-meson-gpio.o