vdr-addon: add noad

Not of much use today.
Needed when vnsiserver and/or xvdr support pvr-api-1.7.0.

see:
https://github.com/opdenkamp/xbmc-pvr-addons/commit/121b7c7b2a7b3f49518a5bdcaf1c2fc28baaa0c9
https://github.com/pipelka/xbmc-addon-xvdr/commit/67cada1fc0216ad090ef79f2818c4e31a4dfa1c8