drm: Remove pending_read_domains and pending_write_domain

The last user of these (i915.ko) no longer does. We can slim down the
core GEM object by removing the unused 8 bytes.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170705154900.28697-1-chris@chris-wilson.co.uk

include/drm/drm_gem.h

@@ -130,21 +130,6 @@ struct drm_gem_object {
 	 */
 	uint32_t write_domain;
 
-	/**
-	 * @pending_read_domains:
-	 *
-	 * While validating an exec operation, the
-	 * new read/write domain values are computed here.
-	 * They will be transferred to the above values
-	 * at the point that any cache flushing occurs
-	 */
-	uint32_t pending_read_domains;
-
-	/**
-	 * @pending_write_domain: Write domain similar to @pending_read_domains.
-	 */
-	uint32_t pending_write_domain;
-
 	/**
 	 * @dma_buf:
 	 *