It will either be Cosworth or Xap (
http://www.xap.fr/) France most probably. However it could be a small outfit that is off the usual radar, or a simple in house operation.
Needles in heystacks this could be.
The MES display is used in F1 and in LMS by Peugoet as their drivers are most comfortable with that display. CART/IRL use a outdated Cosworth display, but are moving over to a new display for the 2012 car. Superleague Formula use Cosworth, WSR and GP2/GP3 use a Xap display that is pretty much the same accross the 3 formule, however the new WSR 2012 car has a wheel and display with 2 new buttons i belive, one for DRS and one that is currently blank that could eventually be used for KERS id guess.
There is a move from the GP2 guys for the GP2 wheel to have the MES display and a couple of settings they can tinker with thru the race as this would give them less to learn coming into a F1 car. However this will probably come in in the next generation GP2 car in 2013/2014 after this one has had its 3 year cycle consumed.