Rename hostDrv -> crossDrv, buildDrv -> nativeDrv

This is for consistency with terminology in stdenv (and the terms
"hostDrv" and "buildDrv" are not very intuitive, even if they're
consistent with GNU terminology).

pkgs/development/libraries/libtheora/default.nix

@@ -10,7 +10,7 @@ stdenv.mkDerivation ({
   propagatedBuildInputs = [libogg libvorbis];
 
   crossAttrs = {
-    propagatedBuildInputs = [libogg.hostDrv tremor.hostDrv];
+    propagatedBuildInputs = [libogg.crossDrv tremor.crossDrv];
     configureFlags = "--disable-examples";
   };
 }