Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/virt/lib/Kconfig b/virt/lib/Kconfig
index 89a414f..2d9523b 100644
--- a/virt/lib/Kconfig
+++ b/virt/lib/Kconfig
@@ -1,2 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
 config IRQ_BYPASS_MANAGER
 	tristate