drm/ttm: Hide the implementation details of reservation

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

diff --cc drivers/gpu/drm/qxl/qxl_release.c
Simple merge

diff --cc drivers/gpu/drm/ttm/ttm_bo.c
Simple merge

diff --cc drivers/gpu/drm/ttm/ttm_execbuf_util.c
Simple merge

diff --cc include/drm/ttm/ttm_bo_driver.h
Simple merge