sched: use sysctl to control energy aware feature

Energy aware feature control is previously done through debugfs,
which will be deprecated, so move the control to sysctl.

Bug: 141333728
Test: function works as expected
Change-Id: I55411d3bb2669ba1fae3225d67cdf1cf8b3b3a7f
Signed-off-by: Rick Yiu <rickyiu@google.com>