Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index 0d15a12..54e4d8b 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* dummy.c: a dummy net driver
 
 	The purpose of this driver is to provide a device to point a
@@ -32,6 +33,7 @@
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
+#include <linux/ethtool.h>
 #include <linux/init.h>
 #include <linux/moduleparam.h>
 #include <linux/rtnetlink.h>
@@ -131,21 +133,9 @@
 	strlcpy(info->version, DRV_VERSION, sizeof(info->version));
 }
 
-static int dummy_get_ts_info(struct net_device *dev,
-			      struct ethtool_ts_info *ts_info)
-{
-	ts_info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE |
-				   SOF_TIMESTAMPING_RX_SOFTWARE |
-				   SOF_TIMESTAMPING_SOFTWARE;
-
-	ts_info->phc_index = -1;
-
-	return 0;
-};
-
 static const struct ethtool_ops dummy_ethtool_ops = {
 	.get_drvinfo            = dummy_get_drvinfo,
-	.get_ts_info		= dummy_get_ts_info,
+	.get_ts_info		= ethtool_op_get_ts_info,
 };
 
 static void dummy_setup(struct net_device *dev)