HID: move to_hid_device() to hid.h

to_hid_device() macro is defined in both hid-lg4ff.c and
hid-logitech-hidpp.c. So I move it to include/linux/hid.h.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/include/linux/hid.h b/include/linux/hid.h
index a6d7a3f..1472026 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -565,6 +565,9 @@
 	wait_queue_head_t debug_wait;
 };
 
+#define to_hid_device(pdev) \
+	container_of(pdev, struct hid_device, dev)
+
 static inline void *hid_get_drvdata(struct hid_device *hdev)
 {
 	return dev_get_drvdata(&hdev->dev);