Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/arm/mach-tango/pm.h b/arch/arm/mach-tango/pm.h
new file mode 100644
index 0000000..35ea705
--- /dev/null
+++ b/arch/arm/mach-tango/pm.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifdef CONFIG_SUSPEND
+void __init tango_pm_init(void);
+#else
+#define tango_pm_init NULL
+#endif