[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/lasat/interrupt.c b/arch/mips/lasat/interrupt.c
index 9316a02..456be8f 100644
--- a/arch/mips/lasat/interrupt.c
+++ b/arch/mips/lasat/interrupt.c
@@ -69,7 +69,7 @@
 		enable_lasat_irq(irq);
 }
 
-static struct hw_interrupt_type lasat_irq_type = {
+static struct irq_chip lasat_irq_type = {
 	.typename = "Lasat",
 	.startup = startup_lasat_irq,
 	.shutdown = shutdown_lasat_irq,