drm/nouveau/cipher: switch to gpuobj accessor macros

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/cipher/g84.c b/drivers/gpu/drm/nouveau/nvkm/engine/cipher/g84.c
index ddc240d..312df6f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/cipher/g84.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/cipher/g84.c
@@ -47,10 +47,12 @@
 	if (ret)
 		return ret;
 
-	nv_wo32(obj, 0x00, nv_mclass(obj));
-	nv_wo32(obj, 0x04, 0x00000000);
-	nv_wo32(obj, 0x08, 0x00000000);
-	nv_wo32(obj, 0x0c, 0x00000000);
+	nvkm_kmap(obj);
+	nvkm_wo32(obj, 0x00, nv_mclass(obj));
+	nvkm_wo32(obj, 0x04, 0x00000000);
+	nvkm_wo32(obj, 0x08, 0x00000000);
+	nvkm_wo32(obj, 0x0c, 0x00000000);
+	nvkm_done(obj);
 	return 0;
 }