Input: touchscreens - switch to using input_dev->dev.parent

In preparation for struct class_device -> struct device input
core conversion, switch to using input_dev->dev.parent when
specifying device position in sysfs tree.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/mtouch.c b/drivers/input/touchscreen/mtouch.c
index 53b0683..4ec3b1f 100644
--- a/drivers/input/touchscreen/mtouch.c
+++ b/drivers/input/touchscreen/mtouch.c
@@ -150,6 +150,7 @@
 	input_dev->id.vendor = SERIO_MICROTOUCH;
 	input_dev->id.product = 0;
 	input_dev->id.version = 0x0100;
+	input_dev->dev.parent = &serio->dev;
 	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
 	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
 	input_set_abs_params(mtouch->dev, ABS_X, MTOUCH_MIN_XC, MTOUCH_MAX_XC, 0, 0);