no_overlay bttv parameter implemented to fix OOPS on some PCI chipsets
(like some VIA) with these behaviors:

1) If pci_quicks does identify the chip as having troubles to
   handle PCI2PCI transfers, no_overlay defaults to 1. The user may force
   it to 0, to reenable (not recommended).

2) For newer chipsets not blacklisted, no_overlay=1 is provided as a
   workaround until PCI chipset included on /drivers/pci/quirks.c

Thanks to Bodo Eggert <7eggert@gmx.de>
Signed-off-by: NMichael Krufky <mkrufky@m1k.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>