ACPI: button: make real parent for input devices in device tree

Signed-off-by: Andrey Borzenkov <arvidjaar@mail.ru>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index 24a7865..6c5da83 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -449,6 +449,7 @@
 	input->phys = button->phys;
 	input->id.bustype = BUS_HOST;
 	input->id.product = button->type;
+	input->dev.parent = &device->dev;
 
 	switch (button->type) {
 	case ACPI_BUTTON_TYPE_POWER: