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/cm-x270.c b/arch/arm/mach-pxa/cm-x270.c
index 4ebcee5..431ef56 100644
--- a/arch/arm/mach-pxa/cm-x270.c
+++ b/arch/arm/mach-pxa/cm-x270.c
@@ -380,7 +380,7 @@
 		.modalias		= "libertas_spi",
 		.max_speed_hz		= 13000000,
 		.bus_num		= 2,
-		.irq			= gpio_to_irq(95),
+		.irq			= PXA_GPIO_TO_IRQ(95),
 		.chip_select		= 0,
 		.controller_data	= &cm_x270_libertas_chip,
 		.platform_data		= &cm_x270_libertas_pdata,