Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index 6d3635c..f9a0c61 100644
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -36,6 +36,7 @@
 int try_stop_cpus(const struct cpumask *cpumask, cpu_stop_fn_t fn, void *arg);
 void stop_machine_park(int cpu);
 void stop_machine_unpark(int cpu);
+void stop_machine_yield(const struct cpumask *cpumask);
 
 #else	/* CONFIG_SMP */