Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h
index 11c86fb..6694d00 100644
--- a/include/linux/semaphore.h
+++ b/include/linux/semaphore.h
@@ -1,9 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (c) 2008 Intel Corporation
  * Author: Matthew Wilcox <willy@linux.intel.com>
  *
- * Distributed under the terms of the GNU GPL, version 2
- *
  * Please see kernel/locking/semaphore.c for documentation of these functions
  */
 #ifndef __LINUX_SEMAPHORE_H