brcm47xx-2.6: add a few nops here, some irq saving there, blast the full cache on page icache flushes
i really hate the broadcom cpu bugs, but it's much more stable now.
PS: A /* Ouch */ in the original source showed me the way ;)


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@8165 3c298f89-4303-0410-b956-a3cf2f4a3e73