ARM: pxa: rename gpio_to_irq and irq_to_gpio

Avoid to define gpio_to_irq() and irq_to_gpio() for potential name
confliction since multiple architecture will be built together.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
diff --git a/arch/arm/mach-mmp/include/mach/irqs.h b/arch/arm/mach-mmp/include/mach/irqs.h
index a09d328..ec95951 100644
--- a/arch/arm/mach-mmp/include/mach/irqs.h
+++ b/arch/arm/mach-mmp/include/mach/irqs.h
@@ -221,6 +221,7 @@
 #define IRQ_GPIO_START			128
 #define IRQ_GPIO_NUM			192
 #define IRQ_GPIO(x)			(IRQ_GPIO_START + (x))
+#define MMP_GPIO_TO_IRQ(gpio)		(IRQ_GPIO_START + (gpio))
 
 #define IRQ_BOARD_START			(IRQ_GPIO_START + IRQ_GPIO_NUM)