docker: Update Broadcom submodule handling

Refactor the handling of the Broadcom firmware submodule to ensure it is synchronized and updated correctly. This change improves the reliability of the build process for the Broadcom platform.

Signed-off-by: Chiho Sin <[email protected]>

Author: chihosin

Containerfile

@@ -45,7 +45,8 @@ ARG BUILD_PLATFORM
 
 # Broadcom
 RUN if [ "${BUILD_PLATFORM}" = "broadcom" ]; then \
-    git -C ports/broadcom/firmware fetch --all --tags; \
+    git submodule sync --recursive; \
+    git submodule update --init --recursive --filter=tree:0 ports/broadcom/firmware; \
 fi
 
 RUN if [ "${BUILD_PLATFORM}" != "zephyr-cp" ]; then \