drm/i915: Fix resume regression on MSI Wind U100 w/o KMS

Commit cbda12d77e (drm/i915: implement
new pm ops for i915), among other things, removed the .suspend and
.resume pointers from the struct drm_driver object in i915_drv.c,
which broke resume without KMS on my MSI Wind U100.

Fix this by reverting that part of commit cbda12d77e.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[anholt: added comment explaining when .suspend/.resume matter]
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_drv.c

@@ -464,6 +464,11 @@ static struct drm_driver driver = {
 	.lastclose = i915_driver_lastclose,
 	.preclose = i915_driver_preclose,
 	.postclose = i915_driver_postclose,
+
+	/* Used in place of i915_pm_ops for non-DRIVER_MODESET */
+	.suspend = i915_suspend,
+	.resume = i915_resume,
+
 	.device_is_agp = i915_driver_device_is_agp,
 	.enable_vblank = i915_enable_vblank,
 	.disable_vblank = i915_disable_vblank,