MAINTAINERS: Add Energy Model framework as properly maintained

The Energy Model framework had some recent grow and became a bit
more complex. Add the proper contact points to maintainers so
other developers can get the right support.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/20250220114103.515278-1-lukasz.luba@arm.com


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>