[package] add a workaround for devices that only start beaconing after...

[package] add a workaround for devices that only start beaconing after scanning, that is almost every driver except b43

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15041 3c298f89-4303-0410-b956-a3cf2f4a3e73