MIPS: Add support for the IMG Pistachio SoC

Add initial support for boards based on the Imagination Pistachio SoC.
Pistachio is based on a dual-core MIPS interAptiv CPU and will boot
using device-tree.

Signed-off-by: James Hartley <james.hartley@imgtec.com>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9569/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/pistachio/irq.c

@@ -0,0 +1,28 @@
+/*
+ * Pistachio IRQ setup
+ *
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/mips-gic.h>
+#include <linux/kernel.h>
+
+#include <asm/cpu-features.h>
+#include <asm/irq_cpu.h>
+
+void __init arch_init_irq(void)
+{
+	pr_info("EIC is %s\n", cpu_has_veic ? "on" : "off");
+	pr_info("VINT is %s\n", cpu_has_vint ? "on" : "off");
+
+	if (!cpu_has_veic)
+		mips_cpu_irq_init();
+
+	irqchip_init();
+}