conf: Add cip's -st branch as a tracking branch
We started self maintenance of 4.4 series. so, it would be nice to add cip's -st branch as a tracking branch.
Because of adding new branch, run scripts/prepare_remotes.py to update remote branch setting is required.
Fixed revision(s) is look like following in yaml file.
cip/4.4-st: [03eed7afbc09e061f66b448daf7863174c3dc3f3]