Don't refer to relative config files in config ref
Don't refer to relative config files in config ref

Readthedocs builds documentation in the doc/source dir, and openstackci
builds the documentation in the networking-cisco root directory, so we
can't use relative paths because they won't be right in both cases.

Change-Id: Ic37e948513b8102fca81ef55872ef68a4746d047

openstack/networking-cisco,noironetworks/networking-cisco,openstack/networking-cisco,noironetworks/networking-cisco,Tehsmash/networking-cisco,Tehsmash/networking-cisco