ARM: SPEAr3xx: Shirq: Move shirq controller out of plat/

This patch moves shirq interrupt controllers driver and header file out of
plat-spear directory. It is moved to drivers/irqchip/ directory.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 054321d..bf7b436 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -1 +1,2 @@
-obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o
+obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2835.o
+obj-$(CONFIG_ARCH_SPEAR3XX)		+= spear-shirq.o