[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/sni/irq.c b/arch/mips/sni/irq.c
index c19e158..cda165f 100644
--- a/arch/mips/sni/irq.c
+++ b/arch/mips/sni/irq.c
@@ -55,7 +55,7 @@
 		enable_pciasic_irq(irq);
 }
 
-static struct hw_interrupt_type pciasic_irq_type = {
+static struct irq_chip pciasic_irq_type = {
 	.typename = "ASIC-PCI",
 	.startup = startup_pciasic_irq,
 	.shutdown = shutdown_pciasic_irq,