ARM: SAMSUNG: Add common samsung_gpiolib_to_irq function

This patch adds a common callback for gpio_to_irq() for external and
gpio interrupts for Samsung SoCs.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
[kgene.kim@samsung.com: moved samsung_gpiolib_to_irq() for s3c24xx build]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/plat-s5p/irq-gpioint.c b/arch/arm/plat-s5p/irq-gpioint.c
index 32263a3..768fd39 100644
--- a/arch/arm/plat-s5p/irq-gpioint.c
+++ b/arch/arm/plat-s5p/irq-gpioint.c
@@ -234,6 +234,7 @@
 	/* register gpio group */
 	ret = s5p_gpioint_add(my_chip);
 	if (ret == 0) {
+		my_chip->chip.to_irq = samsung_gpiolib_to_irq;
 		printk(KERN_INFO "Registered interrupt support for gpio group %d.\n",
 		       group);
 		return my_chip->irq_base + offset;