Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig
index bb30128..dc1a3c4 100644
--- a/drivers/vfio/platform/Kconfig
+++ b/drivers/vfio/platform/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 config VFIO_PLATFORM
 	tristate "VFIO support for platform devices"
 	depends on VFIO && EVENTFD && (ARM || ARM64)