[MIPS] Eleminate interrupt migration helper use.

> #define hw_interrupt_type       irq_chip
> typedef struct irq_chip         hw_irq_controller;
> #define no_irq_type             no_irq_chip
> typedef struct irq_desc         irq_desc_t;

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c
index 0e455a8..9bb21c7 100644
--- a/arch/mips/kernel/irq_cpu.c
+++ b/arch/mips/kernel/irq_cpu.c
@@ -94,7 +94,7 @@
 		unmask_mips_irq(irq);
 }
 
-static hw_irq_controller mips_cpu_irq_controller = {
+static struct irq_chip mips_cpu_irq_controller = {
 	.typename	= "MIPS",
 	.startup	= mips_cpu_irq_startup,
 	.shutdown	= mips_cpu_irq_shutdown,
@@ -140,7 +140,7 @@
 
 #define mips_mt_cpu_irq_end mips_cpu_irq_end
 
-static hw_irq_controller mips_mt_cpu_irq_controller = {
+static struct irq_chip mips_mt_cpu_irq_controller = {
 	.typename	= "MIPS",
 	.startup	= mips_mt_cpu_irq_startup,
 	.shutdown	= mips_mt_cpu_irq_shutdown,