CI Lint with librecores github action linter

Add the librecores linter, that also does proper annotation to the
source code.

.github/workflows/ci.yml

@@ -33,11 +33,6 @@ jobs:
         cd $SERV/workspace
         fusesoc library add serv $SERV
 
-    - name: lint
-      run: |
-        cd $SERV/workspace
-        fusesoc run --target=lint serv
-
     - name: build servant
       run: |
         cd $SERV/workspace

.github/workflows/lint.yml

@@ -0,0 +1,16 @@
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    name: Linter
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v1
+      - name: Lint Verilog source files with Verilator
+        uses: librecores/ci-fusesoc-action@master
+        with:
+          command: 'run'
+          core: 'serv'
+          target: 'lint'
+          tool: 'verilator'

serv.core

@@ -38,6 +38,8 @@ targets:
     tools:
       verilator:
         mode : lint-only
+        verilator_options:
+          - "-Wall"
     toplevel : serv_rf_top
 
 parameters: