drm/amdgpu: Hook up documentation about memory domains

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Documentation/gpu/amdgpu.rst

@@ -10,6 +10,14 @@ Core Driver Infrastructure
 
 This section covers core driver infrastructure.
 
+.. _amdgpu_memory_domains:
+
+Memory Domains
+--------------
+
+.. kernel-doc:: include/uapi/drm/amdgpu_drm.h
+   :doc: memory domains
+
 PRIME Buffer Sharing
 --------------------