ethtool: update to 6.4

ethtool: update to 6.4

ChangeLog:
125b080 Release version 6.4.
5660918 update UAPI header copies
f493e63 netlink: fix duplex setting
b3e341c cmis: report LOL / LOS / Tx Fault
045d8db sff-8636: report LOL / LOS / Tx Fault
a6505f3 drop checks for macros provided in UAPI header copies
86c0c41 do not check for strtol() function
dd8e3ae actually check for C11 compiler
43e4d30 add local copies of macros from autoconf-archive
faa4700 drop check for big endian types
31b7b5e Require a compiler with support for C11 features
946d18b update UAPI header copies
eebf01f ethtool: Add support for configuring tx-push-buf-len
2782ea8 update UAPI header copies

Signed-off-by: Nick Hainke <vincent@systemli.org>