Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/ABI/testing/sysfs-bus-intel_th-output-devices b/Documentation/ABI/testing/sysfs-bus-intel_th-output-devices
index 4d48a94..d1f6671 100644
--- a/Documentation/ABI/testing/sysfs-bus-intel_th-output-devices
+++ b/Documentation/ABI/testing/sysfs-bus-intel_th-output-devices
@@ -3,11 +3,13 @@
 KernelVersion:	4.3
 Contact:	Alexander Shishkin <alexander.shishkin@linux.intel.com>
 Description:	(RW) Writes of 1 or 0 enable or disable trace output to this
-		output device. Reads return current status.
+		output device. Reads return current status. Requires that the
+		correstponding output port driver be loaded.
 
 What:		/sys/bus/intel_th/devices/<intel_th_id>-msc<msc-id>/port
 Date:		June 2015
 KernelVersion:	4.3
 Contact:	Alexander Shishkin <alexander.shishkin@linux.intel.com>
 Description:	(RO) Port number, corresponding to this output device on the
-		switch (GTH).
+		switch (GTH) or "unassigned" if the corresponding output
+		port driver is not loaded.