Add a pm3386 hook for disabling/enabling the SERDES carrier, so that
we can disable it when the interface is administratively downed, and
enable it when it is upped.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NJeff Garzik <jgarzik@pobox.com>