drm/damdgpu:add new mqd member in ring

introduce a new mqd member in ring is for later usage.
we need keep a clean version of MQD for the purpose
of recovering compute rings from hang.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h

@@ -161,6 +161,8 @@ struct amdgpu_ring {
 	u32			pipe;
 	u32			queue;
 	struct amdgpu_bo	*mqd_obj;
+	uint64_t                mqd_gpu_addr;
+	struct vi_mqd           *mqd_ptr;
 	u32			doorbell_index;
 	bool			use_doorbell;
 	unsigned		wptr_offs;

drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c

@@ -4596,6 +4596,8 @@ static void gfx_v8_0_cp_compute_fini(struct amdgpu_device *adev)
 
 			amdgpu_bo_unref(&ring->mqd_obj);
 			ring->mqd_obj = NULL;
+			ring->mqd_ptr = NULL;
+			ring->mqd_gpu_addr = 0;
 		}
 	}
 }