srvcfg: Updated for dynamic service/socket mgmt

Fixed srvcfg crash manager issue, by doing the service &
socket unit file queries dynamically and exposing the objects
to be controlled. This takes care of instanced service &
socket files like phosphor-ipmi-net@eth0 or
phosphor-ipmi-net@eth1 dynamically.

Tested:
1. Verified as per the base service name, all the instanced
service & socket names are dynamically queried and exposed
2. Made sure to list the disabled services thorugh this method
3. Made sure new services listed after fw-update are also
exposed as objects
4. Verfied phosphor-ipmi-net@eth0 port change using ipmitool
-p <newport> option
5. Verified permanent disable of the unit.
6. Verified run time enable / disable of the service.
7. Verified phosphor-ipmi-kcs service permanent & run time
enable / disable

Change-Id: Ib933a2fbff73eae4348a5940d350ae7972db03fb
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>
7 files changed