ethtool: Use full 32 bit speed range in ethtool's set_settings

This makes sure the ethtool's set_settings() callback of network
drivers don't ignore the 16 most significant bits when ethtool calls
their set_settings().

All drivers compiled with make allyesconfig on x86_64 have been
updated.

Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>