There is a lot of duplication of work with regards to overlays
and tablets. This moves common tablet settings from the
individual device trees to a common overlay for a more constant
and easier to manage tablet development.
So far only encore has been updated to use this new overlay. Once
fully tested I will roll out seperate changes for each other device
and have the maintainers test it.
Change-Id: I0a80368d8eee6256a4cb233895fcedb689100115
