Update for deprecation of app.controllers

Post-2.3.0-pre.10, we're deprecating the use of the
controllers array of enyo.Application, in favor of making
those just components so we don't have two different component
models in Enyo.  This updates the code in bootplate-mvc
to use that new format.

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)