Input: ads7846 - fix gpio_pendown configuration

The pendown gpio was requested but not configured for input.
Configure it for input.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index e4ee43e..beb754f 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -966,6 +966,13 @@
 				pdata->gpio_pendown);
 			return err;
 		}
+		err = gpio_direction_input(pdata->gpio_pendown);
+		if (err) {
+			dev_err(&spi->dev, "failed to setup pendown GPIO%d\n",
+				pdata->gpio_pendown);
+			gpio_free(pdata->gpio_pendown);
+			return err;
+		}
 
 		ts->gpio_pendown = pdata->gpio_pendown;