[ARM] S3C64XX: add to_irq() support for EINT() GPIO

N group

Add to_irq() function to onvert gpio to irq for external interrupt
group (GPN).

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c64xx/gpiolib.c

@@ -321,6 +321,11 @@ static struct s3c_gpio_cfg gpio_2bit_cfg_eint11 = {
 	.get_pull	= s3c_gpio_getpull_updown,
 };
 
+int s3c64xx_gpio2int_gpn(struct gpio_chip *chip, unsigned pin)
+{
+	return IRQ_EINT(0) + pin;
+}
+
 static struct s3c_gpio_chip gpio_2bit[] = {
 	{
 		.base	= S3C64XX_GPF_BASE,
@@ -353,6 +358,7 @@ static struct s3c_gpio_chip gpio_2bit[] = {
 			.base	= S3C64XX_GPN(0),
 			.ngpio	= S3C64XX_GPIO_N_NR,
 			.label	= "GPN",
+			.to_irq = s3c64xx_gpio2int_gpn,
 		},
 	}, {
 		.base	= S3C64XX_GPO_BASE,