drm/i915: Getter/setter for object attributes

Soon we want to gut a lot of our existing assumptions how many address
spaces an object can live in, and in doing so, embed the drm_mm_node in
the object (and later the VMA).

It's possible in the future we'll want to add more getter/setter
methods, but for now this is enough to enable the VMAs.

v2: Reworked commit message (Ben)
Added comments to the main functions (Ben)
sed -i "s/i915_gem_obj_set_color/i915_gem_obj_ggtt_set_color/" drivers/gpu/drm/i915/*.[ch]
sed -i "s/i915_gem_obj_bound/i915_gem_obj_ggtt_bound/" drivers/gpu/drm/i915/*.[ch]
sed -i "s/i915_gem_obj_size/i915_gem_obj_ggtt_size/" drivers/gpu/drm/i915/*.[ch]
sed -i "s/i915_gem_obj_offset/i915_gem_obj_ggtt_offset/" drivers/gpu/drm/i915/*.[ch]
(Daniel)

v3: Rebased on new reserve_node patch
Changed DRM_DEBUG_KMS to actually work (will need fixing later)

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_trace.h

@@ -46,8 +46,8 @@ TRACE_EVENT(i915_gem_object_bind,
 
 	    TP_fast_assign(
 			   __entry->obj = obj;
-			   __entry->offset = obj->gtt_space->start;
-			   __entry->size = obj->gtt_space->size;
+			   __entry->offset = i915_gem_obj_ggtt_offset(obj);
+			   __entry->size = i915_gem_obj_ggtt_size(obj);
 			   __entry->mappable = mappable;
 			   ),
 
@@ -68,8 +68,8 @@ TRACE_EVENT(i915_gem_object_unbind,
 
 	    TP_fast_assign(
 			   __entry->obj = obj;
-			   __entry->offset = obj->gtt_space->start;
-			   __entry->size = obj->gtt_space->size;
+			   __entry->offset = i915_gem_obj_ggtt_offset(obj);
+			   __entry->size = i915_gem_obj_ggtt_size(obj);
 			   ),
 
 	    TP_printk("obj=%p, offset=%08x size=%x",