Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/firmware-guide/acpi/index.rst b/Documentation/firmware-guide/acpi/index.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+============
+ACPI Support
+============
+
+.. toctree::
+   :maxdepth: 1
+
+   namespace
+   dsd/graph
+   dsd/data-node-references
+   dsd/leds
+   enumeration
+   osi
+   method-customizing
+   method-tracing
+   DSD-properties-rules
+   debug
+   aml-debugger
+   apei/output_format
+   apei/einj
+   gpio-properties
+   i2c-muxes
+   acpi-lid
+   lpit
+   video_extension
+   extcon-intel-int3496