Upcoming mobile Kepler GPUs (such as GK20A) use the platform bus instead
of PCI to which Nouveau is tightly dependent. This patch allows Nouveau
to handle platform devices by:

- abstracting PCI-dependent functions that were typically used for
  resource querying and page mapping,
- introducing a nv_device_is_pci() function that allows to make
  PCI-dependent code conditional,
- providing a nouveau_drm_platform_probe() function that takes a GPU
  platform device to be probed.

Core code as well as engine/subdev drivers are updated wherever possible
to make use of these functions. Some older drivers are too dependent on
PCI to be properly updated, but all newer code on which future chips may
depend should at least be runnable with platform devices.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Certain combinations of hardware can't actually support the maximum
detected speed. Add a quirk list that lists pairs of hostbridge/chip pci
ids and the mode that they should work with.

See https://bugs.freedesktop.org/show_bug.cgi?id=20341Reported-by: NJason Detring <detringj@gmail.com>
Signed-off-by: NIlia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Signed-off-by: NFrancisco Jerez <currojerez@riseup.net>
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

v2:
- make sure not to execute display scripts unless resuming
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

Signed-off-by: NBen Skeggs <bskeggs@redhat.com>