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.c b/drivers/char/drm/mga_drv.c
index 220037a..0cc7c30 100644
--- a/drivers/char/drm/mga_drv.c
+++ b/drivers/char/drm/mga_drv.c
@@ -78,9 +78,6 @@
 	mga_PCI_IDS
 };
 
-extern drm_ioctl_desc_t mga_ioctls[];
-extern int mga_max_ioctl;
-
 static struct drm_driver driver = {
 	.driver_features =
 	    DRIVER_USE_AGP | DRIVER_REQUIRE_AGP | DRIVER_USE_MTRR |
@@ -151,7 +148,7 @@
  * \returns
  * If the device is a PCI G450, zero is returned.  Otherwise 2 is returned.
  */
-int mga_driver_device_is_agp(drm_device_t * dev)
+static int mga_driver_device_is_agp(drm_device_t * dev)
 {
 	const struct pci_dev *const pdev = dev->pdev;