tests/eas/generic.py: Remove configuration item sched_features

The new Energy Model/EAS mainline code does not use the ENERGY_AWARE
sched feature any more.

Disable it temporarily. We don't have feedback from lkml about the new
Energy Model/EAS mainline code yet so I would like to avoid to change
the test code permanently.

Once we can be more certain that this sched feature is not needed any
more it would have to be removed.

This will allow that the generic tests run against a target with the new
Energy Model/EAS mainline code.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>