Revert "FROMLIST: PM / EM: Expose the Energy Model in sysfs"

This reverts commit b8c80a0f. It has not
been accepted upstream and is useful only for debug purpose. An
alternate debugfs interface will be pushed upstream to expose the Energy
Model. Android should use that too. In the meantime, it should be early
enough to remove the sysfs nodes before partners start basing userspace
tools on them.

Bug: 120440300
Change-Id: I8a5f003550df7df9116d4735c8d9ac10ac0aa79c
Signed-off-by: Quentin Perret <quentin.perret@arm.com>