this patch adds the basic notion of FDD and TDD duplexing modes
to the eNB object. So far we've always assume FDD.
Since only Amarisoft eNB supports TDD, the required config
template changes, etc. are only applied there.
The patch also adds a scenario to enable the default TDD config.
Change-Id: I37216b5bfdf527d221913283b6c41d3c8fd6b500