[CHANGELOG] Remove linux-imx repository reference

* The Edgehog project is not using anymore the forked repository but the
original one in GitHub

manifest-pipeline-yocto.yml

@@ -36,7 +36,6 @@ variables:
     edgehog/layers/seco/meta-seco-edgehog-things
     edgehog/layers/seco/meta-seco-edgehog-embedded
     edgehog/layers/external/poky
-    edgehog/layers/external/linux-imx
   #GitLab group containing LAVA tests
   TEST_REPO_URL: "https://gitlab-ci-token:${GITBOT_TOKEN}@git.seco.com/devops/lava-test-suite/lava-test.git"
   TEST_BRANCH: main