Power down phy on disabled switch ports.
Haven't measured this myself yet, but according to this
http://www.8devices.com/community/viewtopic.php?f=6&t=156
it can save about 300mW of power.
[juhosg: fix checkpatch warning]
Signed-off-by: Tobias Diedrich <ranma+openwrt@tdiedrich.de>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@33304 3c298f89-4303-0410-b956-a3cf2f4a3e73