Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/driver-api/rapidio/sysfs.rst b/Documentation/driver-api/rapidio/sysfs.rst
new file mode 100644
index 0000000..540f726
--- /dev/null
+++ b/Documentation/driver-api/rapidio/sysfs.rst
@@ -0,0 +1,7 @@
+=============
+Sysfs entries
+=============
+
+The RapidIO sysfs files have moved to:
+Documentation/ABI/testing/sysfs-bus-rapidio and
+Documentation/ABI/testing/sysfs-class-rapidio