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

Commit cbda12d77ea590082edb6d30bd342a67ebc459e0 (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 cbda12d77ea59.

[ The DRM layer will not use the class-specific suspend/resume functions
if the driver is marked MODESET-aware, and conversely it will not
register the PCI device if the drievr isn't so marked, so you always
end up with _either_ the drm-class suspend/resume _or_ the PCI layer
PM functionality, never both. - Linus ]

Signed-off-by: Rafael J. Wysocki <[e-mail]>
Acked-by: Jesse Barnes <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/gpu/drm/i915/i915_drv.c

···
 	.lastclose = i915_driver_lastclose,
 	.preclose = i915_driver_preclose,
 	.postclose = i915_driver_postclose,
+	.suspend = i915_suspend,
+	.resume = i915_resume,
 	.device_is_agp = i915_driver_device_is_agp,
 	.enable_vblank = i915_enable_vblank,
 	.disable_vblank = i915_disable_vblank,