brcm47xx: b44: start the phy

We did not start the PHY when an external phy was in use. Without this 
patch the driver uses half duplex mode and the switch uses full duplex 
mode, which causes problems.
Thank you fback for spotting this problem.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39719 3c298f89-4303-0410-b956-a3cf2f4a3e73