use register_cli_opts instead of register_opts

oslo.config provides api register_cli_opts
to register multiple opts at once and same
is used in this patch to replace the
register_opts

Change-Id: I80b9bf37308c9e7085947200bc7c393c15e5e29d
Closes-bug: #1336224
Merge "use register_cli_opts instead of register_opts"