Introduce file net/ethtool/common.c for code shared by ioctl and netlink
ethtool interface. Move name tables of features, RSS hash functions,
tunables and PHY tunables into this file.

Signed-off-by: Michal Kubecek <redacted>
---
net/ethtool/Makefile |  2 +-
net/ethtool/common.c | 84 ++++++++++++++++++++++++++++++++++++++++++++
net/ethtool/common.h | 17 +++++++++
net/ethtool/ioctl.c  | 83 ++-----------------------------------------
4 files changed, 104 insertions(+), 82 deletions(-)
create mode 100644 net/ethtool/common.c
create mode 100644 net/ethtool/common.h

diff --git a/net/ethtool/Makefile b/net/ethtool/Makefile
index 482fdb9380fa..11782306593b 100644
--- a/net/ethtool/Makefile
+++ b/net/ethtool/Makefile

@@ -1,6 +1,6 @@

# SPDX-License-Identifier: GPL-2.0

-obj-y				+= ioctl.o
+obj-y				+= ioctl.o common.o

obj-$(CONFIG_ETHTOOL_NETLINK)	+= ethtool_nl.o

diff --git a/net/ethtool/common.c b/net/ethtool/common.c
new file mode 100644
index 000000000000..b0ce420e994e
--- /dev/null
+++ b/net/ethtool/common.c

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note
+
+#include "common.h"
+
+const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN] = {