Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/ABI/testing/sysfs-devices-software_node b/Documentation/ABI/testing/sysfs-devices-software_node
new file mode 100644
index 0000000..85df37d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-devices-software_node
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+What:		/sys/devices/.../software_node/
+Date:		January 2019
+Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
+Description:
+		This directory contains the details about the device that are
+		assigned in kernel (i.e. software), as opposed to the
+		firmware_node directory which contains the details that are
+		assigned for the device in firmware. The main attributes in the
+		directory will show the properties the device has, and the
+		relationship it has to some of the other devices.