drm: init TTM dev_mapping in ttm_bo_device_init()

With dev->anon_inode we have a global address_space ready for operation
right from the beginning. Therefore, there is no need to do a delayed
setup with TTM. Instead, set dev_mapping during initialization in
ttm_bo_device_init() and remove any "if (dev_mapping)" conditions.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

include/drm/ttm/ttm_bo_driver.h

@@ -747,6 +747,7 @@ extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
  * @bdev: A pointer to a struct ttm_bo_device to initialize.
  * @glob: A pointer to an initialized struct ttm_bo_global.
  * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
+ * @mapping: The address space to use for this bo.
  * @file_page_offset: Offset into the device address space that is available
  * for buffer data. This ensures compatibility with other users of the
  * address space.
@@ -758,6 +759,7 @@ extern int ttm_bo_device_release(struct ttm_bo_device *bdev);
 extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
 			      struct ttm_bo_global *glob,
 			      struct ttm_bo_driver *driver,
+			      struct address_space *mapping,
 			      uint64_t file_page_offset, bool need_dma32);
 
 /**