Remove sshd reconfig from lib/ironic

The sshd reconfiguration to listen on port 2222 provides no
benefit and complicates deployment on some systems.  This removes
the reconfiguration and instead just confirms SSH connectivity.
Default SSH host and ports are left configurable, but the port now
reflects the default 22.

Change-Id: Iaf7c71854c3741a505a79037ffb8c86ace74fc27
(cherry picked from commit 867651049a07a087e619a17d05f569188032f7e0)
Merge "Remove sshd reconfig from lib/ironic" into stable/icehouse