clean up kernel modules, remove b44 references, as it's built-in now

openwrt/target/linux/Config.in

openwrt/target/linux/control/kmod-net-b44.control

openwrt/target/linux/generic-2.4/modules.mk

openwrt/target/linux/generic-2.6/modules.mk

openwrt/target/linux/imagebuilder/lists/default.brcm-2.6

openwrt/target/linux/imagebuilder/lists/micro.brcm-2.6

openwrt/target/linux/imagebuilder/lists/pptp.brcm-2.6

openwrt/target/linux/package/hostap/Config.in

openwrt/target/linux/package/madwifi/Config.in