drm: move ttm global code to core drm

I wrote this for the prime sharing work, but I also noticed other external
non-upstream drivers from a large company carrying a similiar patch, so I
may as well ship it in master.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 0ea602d..b875042 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -34,6 +34,7 @@
 #include "ttm/ttm_memory.h"
 #include "ttm/ttm_module.h"
 #include "drm_mm.h"
+#include "drm_global.h"
 #include "linux/workqueue.h"
 #include "linux/fs.h"
 #include "linux/spinlock.h"
@@ -362,7 +363,7 @@
  */
 
 struct ttm_bo_global_ref {
-	struct ttm_global_reference ref;
+	struct drm_global_reference ref;
 	struct ttm_mem_global *mem_glob;
 };
 
@@ -687,8 +688,8 @@
 extern void ttm_mem_io_free(struct ttm_bo_device *bdev,
 				struct ttm_mem_reg *mem);
 
-extern void ttm_bo_global_release(struct ttm_global_reference *ref);
-extern int ttm_bo_global_init(struct ttm_global_reference *ref);
+extern void ttm_bo_global_release(struct drm_global_reference *ref);
+extern int ttm_bo_global_init(struct drm_global_reference *ref);
 
 extern int ttm_bo_device_release(struct ttm_bo_device *bdev);