Feature Request: Linux ethtool bindings

[maximilian-maisel-bl]

Currently, libc does not provide bindings for the ethtool syscalls
from linux/ethtool.h.

This module contains lots of different syscalls. For the project I'm working on
we need the ETHTOOL_GCOALESCE and ETHTOOL_SCOALESCE syscalls.
I can create a PR for these subset later if desired.