spec: enable vdsm-reg to autostart

This patch enables vdsm-reg to autostart for systemd schema or sysv.

Change-Id: I5aad8014ad37838ceb1ab467380fbe9ffc62ae0b
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1152916
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>