irqchip: mtk-sysirq: Add sysirq interrupt polarity support

Mediatek SoCs have interrupt polarity support in sysirq which
allows to invert polarity for given interrupt. Add this support
using hierarchy irq domain.

Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Link: https://lkml.kernel.org/r/1416902662-19281-3-git-send-email-yingjoe.chen@mediatek.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index ec3621d..2029e79 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -39,3 +39,4 @@
 obj-$(CONFIG_BRCMSTB_L2_IRQ)		+= irq-brcmstb-l2.o \
 					   irq-bcm7120-l2.o
 obj-$(CONFIG_KEYSTONE_IRQ)		+= irq-keystone.o
+obj-$(CONFIG_ARCH_MEDIATEK)		+= irq-mtk-sysirq.o