irqchip/tango: Add support for Sigma Designs SMP86xx/SMP87xx interrupt controller

This adds support for the secondary interrupt controller used in Sigma
Designs SMP86xx and SMP87xx chips.

Signed-off-by: Mans Rullgard <mans@mansr.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1453313237-18570-2-git-send-email-mans@mansr.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 715923d..6bdfbce 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -151,6 +151,11 @@
 	help
 	  Enables SysCfg Controlled IRQs on STi based platforms.
 
+config TANGO_IRQ
+	bool
+	select IRQ_DOMAIN
+	select GENERIC_IRQ_CHIP
+
 config TB10X_IRQC
 	bool
 	select IRQ_DOMAIN