[MIPS] EV64120: Include <asm/irq.h> to fix warning.

arch/mips/pci/pci-ev64120.c:10: warning: implicit declaration of function 'allocate_irqno'

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pci/pci-ev64120.c b/arch/mips/pci/pci-ev64120.c
index 9cd859e..a84f594 100644
--- a/arch/mips/pci/pci-ev64120.c
+++ b/arch/mips/pci/pci-ev64120.c
@@ -1,4 +1,5 @@
 #include <linux/pci.h>
+#include <asm/irq.h>
 
 int __init pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
 {