brcm47xx: do not use vlan0 any more.

The Broadcom switch driver says that vlan0 should not be used with any switch other than bcm5325.

This makes OpenWrt always use vlan1 and vlan2 instead.



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35704 3c298f89-4303-0410-b956-a3cf2f4a3e73