tf-m-static: Use ci-scripts fetch refspec which includes refs/changes/*

To be able to directly test tf-m-ci-scripts patches submitted to Gerrit.

Addresses https://linaro.atlassian.net/browse/TFC-639

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
Change-Id: I701d4f6e5f75c13afd12f654b0011a14a20dd81c
1 file changed