[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/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c
index 1d280aa..8d49cb5 100644
--- a/arch/mips/sibyte/sb1250/irq.c
+++ b/arch/mips/sibyte/sb1250/irq.c
@@ -69,7 +69,7 @@
 #endif
 #endif
 
-static struct hw_interrupt_type sb1250_irq_type = {
+static struct irq_chip sb1250_irq_type = {
 	.typename = "SB1250-IMR",
 	.startup = startup_sb1250_irq,
 	.shutdown = shutdown_sb1250_irq,
@@ -120,7 +120,7 @@
 {
 	int i = 0, old_cpu, cpu, int_on;
 	u64 cur_ints;
-	irq_desc_t *desc = irq_desc + irq;
+	struct irq_desc *desc = irq_desc + irq;
 	unsigned long flags;
 
 	i = first_cpu(mask);
@@ -248,7 +248,7 @@
 			irq_desc[i].chip = &sb1250_irq_type;
 			sb1250_irq_owner[i] = 0;
 		} else {
-			irq_desc[i].chip = &no_irq_type;
+			irq_desc[i].chip = &no_irq_chip;
 		}
 	}
 }
@@ -271,7 +271,7 @@
 
 int sb1250_steal_irq(int irq)
 {
-	irq_desc_t *desc = irq_desc + irq;
+	struct irq_desc *desc = irq_desc + irq;
 	unsigned long flags;
 	int retval = 0;