drm: fix all sparse warning on 32-bit x86

Finally cleaned up the sparse warnings for the drm.

Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/mga_drv.h b/drivers/char/drm/mga_drv.h
index 05f0f91..474853d 100644
--- a/drivers/char/drm/mga_drv.h
+++ b/drivers/char/drm/mga_drv.h
@@ -148,6 +148,9 @@
 	unsigned int agp_pages;
 } drm_mga_private_t;
 
+extern drm_ioctl_desc_t mga_ioctls[];
+extern int mga_max_ioctl;
+
 				/* mga_dma.c */
 extern int mga_driver_preinit(drm_device_t * dev, unsigned long flags);
 extern int mga_dma_bootstrap(DRM_IOCTL_ARGS);