sched: deprecate sched_is_energy_aware() and energy_aware()

sched_energy_present can be used to check if EAS is enabled or not,
and there is no need of additional functions like sched_is_energy_aware()
& energy_aware().

Change-Id: I7e5697d556d1edacd88cf3c6f2c9480bd769f4bc
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>