[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/dec/ioasic-irq.c b/arch/mips/dec/ioasic-irq.c
index da2dbb4..41cd2a9 100644
--- a/arch/mips/dec/ioasic-irq.c
+++ b/arch/mips/dec/ioasic-irq.c
@@ -93,7 +93,7 @@
 		enable_ioasic_irq(irq);
 }
 
-static struct hw_interrupt_type ioasic_irq_type = {
+static struct irq_chip ioasic_irq_type = {
 	.typename = "IO-ASIC",
 	.startup = startup_ioasic_irq,
 	.shutdown = shutdown_ioasic_irq,
@@ -121,7 +121,7 @@
 	end_ioasic_irq(irq);
 }
 
-static struct hw_interrupt_type ioasic_dma_irq_type = {
+static struct irq_chip ioasic_dma_irq_type = {
 	.typename = "IO-ASIC-DMA",
 	.startup = startup_ioasic_dma_irq,
 	.shutdown = shutdown_ioasic_dma_irq,