irqchip: add nps Internal and external irqchips

Adding EZchip NPS400 support.
Internal interrupts are handled by Multi Thread Manager (MTM)
Once interrupt is serviced MTM is acked for deactivating the interrupt.
External interrupts are handled by MTM as well as at Global Interrupt
Controller (GIC) e.g. serial and network devices.

Signed-off-by: Noam Camus <noamc@ezchip.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3e12479..1ab632a 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -244,3 +244,9 @@
 config MVEBU_ODMI
 	bool
 	select GENERIC_MSI_IRQ_DOMAIN
+
+config EZNPS_GIC
+	bool "NPS400 Global Interrupt Manager (GIM)"
+	select IRQ_DOMAIN
+	help
+	  Support the EZchip NPS400 global interrupt controller