drm: Extract drm_ioctl.h

To match the drm_ioctl.c we already have.

v2: Remove spurious space (Ville).

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index a7c61c2..7d6deaa 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -28,6 +28,7 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
+#include <drm/drm_ioctl.h>
 #include <drm/drmP.h>
 #include <drm/drm_auth.h>
 #include "drm_legacy.h"