Revert "input/hog: Remove HID device after HoG device disconnects"

This reverts commit d6cafa1.

In commit d6cafa1 ("input/hog: Remove HID device after HoG device
disconnects"), the bt_hog structure is destroyed in order to fix a bug
where the UHID connection is not destroyed. This fix has the cost of
increasing reconnection time because every reconnection would need to
re-read the report map again. An improvement to this fix is, instead of
removing the bt_hog structure, we can just destroy the UHID with
UHID_DESTROY event and use the existing bt_hog structure to keep the
cache of the report map to avoid re-reading the report map at
reconnection.

profiles/input/hog.c

@@ -207,8 +207,6 @@ static int hog_disconnect(struct btd_service *service)
 	struct hog_device *dev = btd_service_get_user_data(service);
 
 	bt_hog_detach(dev->hog);
-	bt_hog_unref(dev->hog);
-	dev->hog = NULL;
 
 	btd_service_disconnecting_complete(service, 0);