[AGPGART] SIS AGP updates

[AGPGART] SIS AGP updates

Signed-off-by: Dave Jones <davej@redhat.com>
From: "Heilmann, Oliver" <Oliver.Heilmann@drkw.com>

* renamed sis_648_enable to sis_delayed_enable and removed chipset
  references

* All chipsets that require the sis delay-hack are listed in
  sis_broken_chipsets (and no other place).

* There are two new module options to force agp3-spec compliant
  initialisation and/or the delay hack.  As I only have a 648FX chipset to
  test on, I figured this might be useful to experiment with on other
  chipsets (i.e.746[FX]).

Basically, if you have an  SiS chipset and your machine freezes when you
start X, try the -agp_sis_force_delay=1 option. If this fixes your
problem add your PCI ID to sis_broken_chipsets in sis-agp.c
Note to 746[FX] people: I'm still not sure what the differences between
the two 746 versions and the 648 series are. If this patch does not work
for you try playing with the agp_sis_agp_spec module option. Any
feedback is greatly appreciated.