Give upstream as a argument to workflow call

Signed-off-by: peppi-lotta <[email protected]>

Author: peppi-lotta

.github/workflows/pr-link-check.yml

@@ -10,3 +10,5 @@ permissions:
 jobs:
   check-pr-links:
     uses: metal3-io/project-infra/.github/workflows/pr-link-check.yml@main
+    with:
+      upstream: https://github.com/metal3-io/metal3-docs.git