ARM: EXYNOS: fix touchscreen IRQ setup on Universal C210 board

Fixes atmel_mxt_ts freeze on Universal C210.

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
diff --git a/arch/arm/mach-exynos/mach-universal_c210.c b/arch/arm/mach-exynos/mach-universal_c210.c
index 0fc65ff..3893995 100644
--- a/arch/arm/mach-exynos/mach-universal_c210.c
+++ b/arch/arm/mach-exynos/mach-universal_c210.c
@@ -13,6 +13,7 @@
 #include <linux/i2c.h>
 #include <linux/gpio_keys.h>
 #include <linux/gpio.h>
+#include <linux/interrupt.h>
 #include <linux/fb.h>
 #include <linux/mfd/max8998.h>
 #include <linux/regulator/machine.h>
@@ -595,6 +596,7 @@
 	.threshold	= 0x28,
 	.voltage	= 2800000,		/* 2.8V */
 	.orient		= MXT_DIAGONAL,
+	.irqflags	= IRQF_TRIGGER_FALLING,
 };
 
 static struct i2c_board_info i2c3_devs[] __initdata = {