Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/atm/idt77105.c b/drivers/atm/idt77105.c
index 0a67487..6387185 100644
--- a/drivers/atm/idt77105.c
+++ b/drivers/atm/idt77105.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* drivers/atm/idt77105.c - IDT77105 (PHY) driver */
  
 /* Written 1999 by Greg Banks, NEC Australia <gnb@linuxfan.com>. Based on suni.c */