Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h
index 70e19bc..46b92cd 100644
--- a/include/linux/cacheinfo.h
+++ b/include/linux/cacheinfo.h
@@ -17,6 +17,8 @@
 	CACHE_TYPE_UNIFIED = BIT(2),
 };
 
+extern unsigned int coherency_max_size;
+
 /**
  * struct cacheinfo - represent a cache leaf node
  * @id: This cache's id. It is unique among caches with the same (type, level).