devices: trlte: Update markdown for unified build

* Merge international and americas variants as trlte
* State devicenames/codenames
* Remove oldurl link
* Add link to device tree
* Keep @bigbiff as maintainer so he'll be the one to blame ;)

Change-Id: Idbb7e72309ce5be865e62de4478a8e1ff4dde43f
1 file changed