[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/sgi-ip27/ip27-irq.c b/arch/mips/sgi-ip27/ip27-irq.c
index 52dad1b..24a8537 100644
--- a/arch/mips/sgi-ip27/ip27-irq.c
+++ b/arch/mips/sgi-ip27/ip27-irq.c
@@ -345,7 +345,7 @@
 		enable_bridge_irq(irq);
 }
 
-static struct hw_interrupt_type bridge_irq_type = {
+static struct irq_chip bridge_irq_type = {
 	.typename	= "bridge",
 	.startup	= startup_bridge_irq,
 	.shutdown	= shutdown_bridge_irq,