SSG also updated to account for this and stub out an initial
'get_dping_target' function

also start removing ssg references from swim code

- focus on verbs;ofi_rxm stack for now

- problematic issue has been fixed in libfabric repo

- just keeping in git as a debugging hack to keep time calls from
  showing up in profiles

- no significant perf change with this or preceding cache mode changes, but
  including for completeness