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-pxa/littleton.c b/arch/arm/mach-pxa/littleton.c
index 9cd2356..27147f6 100644
--- a/arch/arm/mach-pxa/littleton.c
+++ b/arch/arm/mach-pxa/littleton.c
@@ -395,7 +395,7 @@
 		.type		= "da9034",
 		.addr		= 0x34,
 		.platform_data	= &littleton_da9034_info,
-		.irq		= gpio_to_irq(mfp_to_gpio(MFP_PIN_GPIO18)),
+		.irq		= PXA_GPIO_TO_IRQ(mfp_to_gpio(MFP_PIN_GPIO18)),
 	},
 	[1] = {
 		.type		= "max7320",