[MIPS] Remove redeclarations of setup_irq().

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/ddb5xxx/ddb5477/setup.c b/arch/mips/ddb5xxx/ddb5477/setup.c
index 47ba0b6..904c8f4 100644
--- a/arch/mips/ddb5xxx/ddb5477/setup.c
+++ b/arch/mips/ddb5xxx/ddb5477/setup.c
@@ -19,6 +19,7 @@
 #include <linux/sched.h>
 #include <linux/pci.h>
 #include <linux/ide.h>
+#include <linux/irq.h>
 #include <linux/fs.h>
 #include <linux/ioport.h>
 #include <linux/param.h>	/* for HZ */
@@ -146,8 +147,6 @@
 	mips_hpt_frequency = bus_frequency*(i+4)/4;
 }
 
-extern int setup_irq(unsigned int irq, struct irqaction *irqaction);
-
 static void __init ddb_timer_setup(struct irqaction *irq)
 {
 #if defined(USE_CPU_COUNTER_TIMER)