MIPS: AR7, BCM63xx: fix gpio_to_irq() return value

The return value of gpio_to_irq() is not a pointer but an integer.

Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org>
Cc: linux-mips <linux-mips@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/1280/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/mach-bcm63xx/gpio.h b/arch/mips/include/asm/mach-bcm63xx/gpio.h
index 7cda8c0..1eb534d 100644
--- a/arch/mips/include/asm/mach-bcm63xx/gpio.h
+++ b/arch/mips/include/asm/mach-bcm63xx/gpio.h
@@ -3,7 +3,7 @@
 
 #include <bcm63xx_gpio.h>
 
-#define gpio_to_irq(gpio)	NULL
+#define gpio_to_irq(gpio)	-1
 
 #define gpio_get_value __gpio_get_value
 #define gpio_set_value __gpio_set_value