[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/momentum/ocelot_c/uart-irq.c b/arch/mips/momentum/ocelot_c/uart-irq.c
index 8522650..9f33d8f 100644
--- a/arch/mips/momentum/ocelot_c/uart-irq.c
+++ b/arch/mips/momentum/ocelot_c/uart-irq.c
@@ -121,7 +121,7 @@
 
 #define shutdown_uart_irq	disable_uart_irq
 
-struct hw_interrupt_type uart_irq_type = {
+struct irq_chip uart_irq_type = {
 	.typename = "UART/FPGA",
 	.startup = startup_uart_irq,
 	.shutdown = shutdown_uart_irq,