Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/Documentation/dev-tools/kcov.rst b/Documentation/dev-tools/kcov.rst
index c2f6452..42b6126 100644
--- a/Documentation/dev-tools/kcov.rst
+++ b/Documentation/dev-tools/kcov.rst
@@ -22,7 +22,7 @@
 
         CONFIG_KCOV=y
 
-CONFIG_KCOV requires gcc built on revision 231296 or later.
+CONFIG_KCOV requires gcc 6.1.0 or later.
 
 If the comparison operands need to be collected, set::