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/pxa25x.c b/arch/arm/mach-pxa/pxa25x.c
index f05f948..0f38cfc 100644
--- a/arch/arm/mach-pxa/pxa25x.c
+++ b/arch/arm/mach-pxa/pxa25x.c
@@ -287,7 +287,7 @@
 
 static int pxa25x_set_wake(struct irq_data *d, unsigned int on)
 {
-	int gpio = irq_to_gpio(d->irq);
+	int gpio = pxa_irq_to_gpio(d->irq);
 	uint32_t mask = 0;
 
 	if (gpio >= 0 && gpio < 85)