CI: check usage of BoringUtils

.github/workflows/emu.yml

@@ -15,6 +15,13 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: 'recursive'
+      - name: Check Wiring
+        run: |
+          grep -rn "BoringUtils" $GITHUB_WORKSPACE/src/main/scala/xiangshan
+          if [[ $? == 0 ]];
+          then
+              exit 1
+          fi
       - name: Set env
         run: |
           echo ::set-env name=NEMU_HOME::/home/ci-runner/xsenv/NEMU