bcm63xx: remove empty directories



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36609 3c298f89-4303-0410-b956-a3cf2f4a3e73
bcm63xx: remove defconfig support

All boards use uci-defaults, no need to keep defconfig support.



git-svn-id: svn://svn.openwrt.org/openwrt/trunk@36610 3c298f89-4303-0410-b956-a3cf2f4a3e73