Added device_is_agp callback to drm_driver. This function is called by the
platform-specific drm_device_is_agp function. Added implementation of this
function the the Linux-specific portion of the MGA driver to detect PCI G450
cards. Added code to the Linux-specific portion of the generic DRM layer to
not initialize AGP infrastructure if the card is not AGP (this matches what
already existed in BSD).
Fix up i810/i830 and i915 drivers to always return AGP as they don't always
report the capability.
Fix the MGA to not report AGP for a card that has an AGP chip behind a PCI
bridge.
From: Ian Romanick, Dave Airlie, Alan Hourihane
Signed-off-by: Dave Airlie <airlied@linux.ie>
cda1738066