drm: add 32/64 support for MGA/R128/i915

This adds compatiblity ioctls for mga/r128 and i915 DRM drivers.

From: Paul Mackerras, David Airlie, Alan Hourihane, Egbert Eich.
Signed-off-by: David Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/i915_drv.c b/drivers/char/drm/i915_drv.c
index e6a9e1d..6a6cc3c 100644
--- a/drivers/char/drm/i915_drv.c
+++ b/drivers/char/drm/i915_drv.c
@@ -97,6 +97,9 @@
 		.mmap = drm_mmap,
 		.poll = drm_poll,
 		.fasync = drm_fasync,
+#ifdef CONFIG_COMPAT
+		.compat_ioctl = i915_compat_ioctl,
+#endif
 	},
 	.pci_driver = {
 		.name          = DRIVER_NAME,