use tag for test dependency commit

Use the output of 'git describe' to pin the commit checked out
for dependency titan.ProtocolModules.SGsAP_13.2.0_commit, i.e.
the tag which points to 81544cf008378058b95ff20d33f3770fadb7e235.

Using a plain commit hash will always re-trigger an update of
the working tree in this particular case because 'git describe'
won't ever return an error.

Change-Id: Ia994b5c4488fd9b0d410b992e515c6eec4dd23b1
1 file changed