Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index 827c601..5167bf2 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * AMD Secure Encrypted Virtualization (SEV) driver interface
  *
@@ -5,12 +6,7 @@
  *
  * Author: Brijesh Singh <brijesh.singh@amd.com>
  *
- * SEV spec 0.14 is available at:
- * http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
+ * SEV API spec is available at https://developer.amd.com/sev
  */
 
 #ifndef __PSP_SEV_H__