The previous workaround didn't enable the BTIC bit on CPUs where it is
broken.  However, it seems some firmwares will unconditionally set it,
so this new patch will actually _clear_ it on CPUs where it is broken.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>