ethtool: provide EEE settings with EEE_GET request

Implement EEE_GET request to get EEE settings of a network device. These
are traditionally available via ETHTOOL_GEEE ioctl request.

The netlink interface allows reporting EEE status for all link modes
supported by kernel but only first 32 link modes are provided at the moment
as only those are reported by the ethtool_ops callback and drivers.

v2: fix alignment (whitespace only)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>