fixup: unresolved_references
don't crash when link is TCLink but without options

caused by optimized return in link.py#275 in TCIntf.config()
Merge pull request #254 from sieben/unresolved_references

fixup: unresolved_references
Merge pull request #264 from adferguson/tc-no_opt-fix

don't crash when link is TCLink but without options