[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.c b/arch/mips/kernel/irq.c
index cde5e5a..d955aae 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -136,7 +136,7 @@
 		irq_desc[i].status  = IRQ_DISABLED;
 		irq_desc[i].action  = NULL;
 		irq_desc[i].depth   = 1;
-		irq_desc[i].chip = &no_irq_type;
+		irq_desc[i].chip = &no_irq_chip;
 		spin_lock_init(&irq_desc[i].lock);
 #ifdef CONFIG_MIPS_MT_SMTC
 		irq_hwmask[i] = 0;