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/mga_drv.h b/drivers/char/drm/mga_drv.h
index 1d84a1e..9412e281 100644
--- a/drivers/char/drm/mga_drv.h
+++ b/drivers/char/drm/mga_drv.h
@@ -137,6 +137,8 @@
 extern void mga_driver_irq_preinstall( drm_device_t *dev );
 extern void mga_driver_irq_postinstall( drm_device_t *dev );
 extern void mga_driver_irq_uninstall( drm_device_t *dev );
+extern long mga_compat_ioctl(struct file *filp, unsigned int cmd,
+			     unsigned long arg);
 
 #define mga_flush_write_combine()	DRM_WRITEMEMORYBARRIER()