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/savage/savage_drv.c

@@ -23,6 +23,8 @@
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/module.h>
+
 #include "drmP.h"
 #include "savage_drm.h"
 #include "savage_drv.h"