gpu: add module.h to drivers/gpu files as required.

So that we don't get build failures once the implicit module.h
presence is removed.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

drivers/gpu/drm/tdfx/tdfx_drv.c

@@ -30,6 +30,8 @@
  *    Gareth Hughes <gareth@valinux.com>
  */
 
+#include <linux/module.h>
+
 #include "drmP.h"
 #include "tdfx_drv.h"