drm/amdgpu: Add documentation for PCIe accounting

Add the amdgpu.rst tie-ins for the pcie accounting documentation
Signed-off-by: Kent Russell <kent.russell@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Documentation/gpu/amdgpu.rst

@@ -257,13 +257,30 @@ mem_info_vis_vram_used
    :doc: mem_info_vis_vram_used
 
 mem_info_gtt_total
------------------------
+------------------
 
 .. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
    :doc: mem_info_gtt_total
 
 mem_info_gtt_used
-------------------
+-----------------
 
 .. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c
    :doc: mem_info_gtt_used
+
+PCIe Accounting Information
+===========================
+
+pcie_bw
+-------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
+   :doc: pcie_bw
+
+pcie_replay_count
+-----------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+   :doc: pcie_replay_count
+
+