Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/powerpc/mm/ptdump/ptdump.h b/arch/powerpc/mm/ptdump/ptdump.h
new file mode 100644
index 0000000..5d51363
--- /dev/null
+++ b/arch/powerpc/mm/ptdump/ptdump.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/types.h>
+
+struct flag_info {
+	u64		mask;
+	u64		val;
+	const char	*set;
+	const char	*clear;
+	bool		is_val;
+	int		shift;
+};
+
+struct pgtable_level {
+	const struct flag_info *flag;
+	size_t num;
+	u64 mask;
+};
+
+extern struct pgtable_level pg_level[5];