Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/scripts/atomic/fallbacks/dec b/scripts/atomic/fallbacks/dec
new file mode 100755
index 0000000..10bbc82
--- /dev/null
+++ b/scripts/atomic/fallbacks/dec
@@ -0,0 +1,7 @@
+cat <<EOF
+static inline ${ret}
+${atomic}_${pfx}dec${sfx}${order}(${atomic}_t *v)
+{
+	${retstmt}${atomic}_${pfx}sub${sfx}${order}(1, v);
+}
+EOF