restapi: Fix watchdog RSDL definitions

This fixes a typo in one RSDL line and adds the watchdogs
subcollection to VM templates.

Change-Id: Iaad4bf13e7862e5cb52aede89297eb5707ca96ae
Bug-Url: https://bugzilla.redhat.com/1129840
Signed-off-by: Martin Sivak <msivak@redhat.com>