CI: Add tf-sync-github-repos.yaml

Mirror TF-A, TF-M, Hafnium, and TS repos into GitHub [1]

[1]: https://linaro.atlassian.net/browse/TFC-247

Signed-off-by: Arthur She <arthur.she@linaro.org>
Change-Id: I03557c2142add7ae8fb245cf3f2918085be120fc
2 files changed