lnst-ctl man page add -r and deconfigure

This commit updates the lnst-ctl manual page to contain information on
the newly added deconfigure action and the -r (--reduce-sync) option.

Signed-off-by: Ondrej Lichtner <olichtne@redhat.com>
Signed-off-by: Jiri Pirko <jiri@resnulli.us>