Changes needed to support per-device patch queues

In order to have per-device patch queues, as requested in bug 832002, we need to have the patching script know to re-patch the tree when we change devices.  Instead of doing something flakey in config.sh, let's just include the .config file (which has the device specified) in the list of files that the patching infrastructure cares about whether or not it's changed.

This is a trivial change.  I'm happy to land without the comment if it's felt to be unnecessary.