Update Dockerfile.multi

Signed-off-by: Yanchao Lu <yanchaol@nvidia.com>

Author: chzblych

docker/Dockerfile.multi

@@ -124,6 +124,7 @@ FROM ${DEVEL_IMAGE} AS wheel
 WORKDIR /src/tensorrt_llm
 COPY benchmarks benchmarks
 COPY cpp cpp
+COPY docker docker
 COPY scripts scripts
 COPY tensorrt_llm tensorrt_llm
 COPY 3rdparty 3rdparty