These can be simplified and merged into the subsystem.
Remove the concept of mappings from subsystems and replace
it with a list of hosts and ports. The host is optional -
not specifying a host means any host can connect.
Change-Id: Ib3786acb40a34b7e10935af55f4b6756d40cc906
Signed-off-by: Ben Walker <benjamin.walker@intel.com>