drm/i915: force mode set at lid open time

Some laptop platforms will disable pipes and/or planes at lid close time
and not restore them when the lid is opened again.  So catch the lid
event, and if the lid was opened, force a mode restore.

Fixes fdo bug #21230.

Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/Kconfig

@@ -102,6 +102,7 @@ config DRM_I915
 	select BACKLIGHT_CLASS_DEVICE if ACPI
 	select INPUT if ACPI
 	select ACPI_VIDEO if ACPI
+	select ACPI_BUTTON if ACPI
 	help
 	  Choose this option if you have a system that has Intel 830M, 845G,
 	  852GM, 855GM 865G or 915G integrated graphics.  If M is selected, the