irqchip: add DesignWare APB ICTL interrupt controller

This adds an irqchip driver and corresponding devicetree binding for the
secondary interrupt controllers based on Synopsys DesignWare IP dw_apb_ictl.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Jisheng Zhang <jszhang@marvell.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c60b901..6427323 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -6,6 +6,7 @@
 obj-$(CONFIG_ARCH_MVEBU)		+= irq-armada-370-xp.o
 obj-$(CONFIG_ARCH_MXS)			+= irq-mxs.o
 obj-$(CONFIG_ARCH_S3C24XX)		+= irq-s3c24xx.o
+obj-$(CONFIG_DW_APB_ICTL)		+= irq-dw-apb-ictl.o
 obj-$(CONFIG_METAG)			+= irq-metag-ext.o
 obj-$(CONFIG_METAG_PERFCOUNTER_IRQS)	+= irq-metag.o
 obj-$(CONFIG_ARCH_MOXART)		+= irq-moxart.o