[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/tx4938/common/irq.c b/arch/mips/tx4938/common/irq.c
index 0b2f8c8..dc30d66 100644
--- a/arch/mips/tx4938/common/irq.c
+++ b/arch/mips/tx4938/common/irq.c
@@ -57,7 +57,7 @@
 DEFINE_SPINLOCK(tx4938_pic_lock);
 
 #define TX4938_CP0_NAME "TX4938-CP0"
-static struct hw_interrupt_type tx4938_irq_cp0_type = {
+static struct irq_chip tx4938_irq_cp0_type = {
 	.typename = TX4938_CP0_NAME,
 	.startup = tx4938_irq_cp0_startup,
 	.shutdown = tx4938_irq_cp0_shutdown,
@@ -69,7 +69,7 @@
 };
 
 #define TX4938_PIC_NAME "TX4938-PIC"
-static struct hw_interrupt_type tx4938_irq_pic_type = {
+static struct irq_chip tx4938_irq_pic_type = {
 	.typename = TX4938_PIC_NAME,
 	.startup = tx4938_irq_pic_startup,
 	.shutdown = tx4938_irq_pic_shutdown,