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/saarb.c b/arch/arm/mach-pxa/saarb.c
index 3e999e3..d1cdd6a 100644
--- a/arch/arm/mach-pxa/saarb.c
+++ b/arch/arm/mach-pxa/saarb.c
@@ -92,7 +92,7 @@
 		.type		= "88PM860x",
 		.addr		= 0x34,
 		.platform_data	= &saarb_pm8607_info,
-		.irq		= gpio_to_irq(mfp_to_gpio(MFP_PIN_GPIO83)),
+		.irq		= PXA_GPIO_TO_IRQ(mfp_to_gpio(MFP_PIN_GPIO83)),
 	},
 };