Display: getRequestedResolution: fallback to getResolution() value

* if not using HDMI, falling back to 720p may cause issues
* Also execute hdmiPlugged() regardless so cvbs users can have settings
  restored on boot as well*

Signed-off-by: Brandon McAnsh <brandonm@matricom.net>
HdmiManager API 2.1 changes

Signed-off-by: Brandon McAnsh <brandonm@matricom.net>