Revert "drm/i915/fbdev: Actually configure untiled displays"

This reverts commit d179b88d.

This commit is documented to break userspace X.org modesetting driver in certain configurations.

The X.org modesetting userspace driver is broken. No fixes are available yet. In order for this patch to be applied it either needs a config option or a workaround developed.

This has been reported a few times, saying it's a userspace problem is clearly against the regression rules.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109806


Signed-off-by: Dave Airlie <airlied@redhat.com>
Cc: <stable@vger.kernel.org> # v3.19+