Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/lasat/picvue.c b/arch/mips/lasat/picvue.c
index d613b97..08298cc 100644
--- a/arch/mips/lasat/picvue.c
+++ b/arch/mips/lasat/picvue.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Picvue PVC160206 display driver
  *