brcm63xx: fix wrong fixups pointer

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42756 3c298f89-4303-0410-b956-a3cf2f4a3e73