Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c
index 738bf42..be5bc2e 100644
--- a/arch/x86/kernel/topology.c
+++ b/arch/x86/kernel/topology.c
@@ -71,7 +71,7 @@
 	case 0:
 		ret = cpu_down(cpu);
 		if (!ret) {
-			pr_info("CPU %u is now offline\n", cpu);
+			pr_info("DEBUG_HOTPLUG_CPU0: CPU %u is now offline\n", cpu);
 			dev->offline = true;
 			kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
 		} else