drm/amd/amdgpu: Fix csb.bo pin_count leak on gfx 9

[Why]
csb bo is not unpinned in gfx 9. It will lead to pin_count leak on
driver unload.

[How]
Call bo_free_kernel corresponding to bo_create_kernel in
gfx_rlc_init_csb. This will also unify the code path with other gfx
versions.
Signed-off-by: YuBiao Wang <YuBiao.Wang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

@@ -2462,7 +2462,9 @@ static int gfx_v9_0_sw_fini(void *handle)
 	amdgpu_gfx_kiq_fini(adev);
 
 	gfx_v9_0_mec_fini(adev);
-	amdgpu_bo_unref(&adev->gfx.rlc.clear_state_obj);
+	amdgpu_bo_free_kernel(&adev->gfx.rlc.clear_state_obj,
+				&adev->gfx.rlc.clear_state_gpu_addr,
+				(void **)&adev->gfx.rlc.cs_ptr);
 	if (adev->flags & AMD_IS_APU) {
 		amdgpu_bo_free_kernel(&adev->gfx.rlc.cp_table_obj,
 				&adev->gfx.rlc.cp_table_gpu_addr,