actions: Add github actions to perform DCO check

Action performs a check to verify PR raised has commits
that are signed-off.

Signed-off-by: Archana Shinde <archana.m.shinde@intel.com>
(cherry picked from commit 1b157e5)

.github/workflows/dco-check.yaml

@@ -0,0 +1,22 @@
+name: DCO check
+on: 
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+
+jobs:
+  dco_check_job:
+    runs-on: ubuntu-latest
+    name: DCO Check
+    steps:
+    - name: Get PR Commits
+      id: 'get-pr-commits'
+      uses: tim-actions/get-pr-commits@master
+      with:
+        token: ${{ secrets.GITHUB_TOKEN }}
+    - name: DCO Check
+      uses: tim-actions/dco@master
+      with:
+        commits: ${{ steps.get-pr-commits.outputs.commits }}