When there will be multiple cells and so multiple DRB files referenced from enb.cfg,
eNB will complain with an error that "there are multiple #define" for T_REORDERING.

-> Use jinja2 templating instead to handle FDD/TDD conditions.

/cc @xavier_thompson, @Daetalus
/reviewed-by @jhuge, @lu.xu
/reviewed-on nexedi/slapos!1473