Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/affs/amigaffs.h b/fs/affs/amigaffs.h
index f9bef90..81fb396 100644
--- a/fs/affs/amigaffs.h
+++ b/fs/affs/amigaffs.h
@@ -32,6 +32,9 @@
 
 #define AFFS_ROOT_BMAPS		25
 
+/* Seconds since Amiga epoch of 1978/01/01 to UNIX */
+#define AFFS_EPOCH_DELTA ((8 * 365 + 2) * 86400LL)
+
 struct affs_date {
 	__be32 days;
 	__be32 mins;